diff --git a/docs/src/api/params.md b/docs/src/api/params.md
index 7066b53dd6..c555008e47 100644
--- a/docs/src/api/params.md
+++ b/docs/src/api/params.md
@@ -523,22 +523,42 @@ Whether to emulate network being offline. Defaults to `false`.
 Credentials for [HTTP authentication](https://developer.mozilla.org/en-US/docs/Web/HTTP/Authentication).
 
 ## context-option-colorscheme
-- `colorScheme` <[ColorScheme]<"light"|"dark"|"no-preference">>
+* langs: js, python, java
+- `colorScheme` <null|[ColorScheme]<"light"|"dark"|"no-preference">>
 
 Emulates `'prefers-colors-scheme'` media feature, supported values are `'light'`, `'dark'`, `'no-preference'`. See
-[`method: Page.emulateMedia`] for more details. Defaults to `'light'`.
+[`method: Page.emulateMedia`] for more details. Passing `null` resets emulation to system defaults. Defaults to `'light'`.
+
+## context-option-colorscheme-csharp
+* langs: csharp
+- `colorScheme` <[ColorScheme]<"light"|"dark"|"no-preference"|"null">>
+
+Emulates `'prefers-colors-scheme'` media feature, supported values are `'light'`, `'dark'`, `'no-preference'`. See
+[`method: Page.emulateMedia`] for more details. Passing `'null'` resets emulation to system defaults. Defaults to `'light'`.
 
 ## context-option-reducedMotion
-- `reducedMotion` <[ReducedMotion]<"reduce"|"no-preference">>
+* langs: js, python, java
+- `reducedMotion` <null|[ReducedMotion]<"reduce"|"no-preference">>
 
-Emulates `'prefers-reduced-motion'` media feature, supported values are `'reduce'`, `'no-preference'`. See [`method: Page.emulateMedia`] for more details. Defaults
-to `'no-preference'`.
+Emulates `'prefers-reduced-motion'` media feature, supported values are `'reduce'`, `'no-preference'`. See [`method: Page.emulateMedia`] for more details. Passing `null` resets emulation to system defaults. Defaults to `'no-preference'`.
+
+## context-option-reducedMotion-csharp
+* langs: csharp
+- `reducedMotion` <[ReducedMotion]<"reduce"|"no-preference"|"null">>
+
+Emulates `'prefers-reduced-motion'` media feature, supported values are `'reduce'`, `'no-preference'`. See [`method: Page.emulateMedia`] for more details. Passing `'null'` resets emulation to system defaults. Defaults to `'no-preference'`.
 
 ## context-option-forcedColors
-- `forcedColors` <[ForcedColors]<"active"|"none">>
+* langs: js, python, java
+- `forcedColors` <null|[ForcedColors]<"active"|"none">>
 
-Emulates `'forced-colors'` media feature, supported values are `'active'`, `'none'`. See [`method: Page.emulateMedia`] for more details. Defaults
-to `'none'`.
+Emulates `'forced-colors'` media feature, supported values are `'active'`, `'none'`. See [`method: Page.emulateMedia`] for more details. Passing `null` resets emulation to system defaults. Defaults to `'none'`.
+
+## context-option-forcedColors-csharp
+* langs: csharp
+- `forcedColors` <[ForcedColors]<"active"|"none"|"null">>
+
+Emulates `'forced-colors'` media feature, supported values are `'active'`, `'none'`. See [`method: Page.emulateMedia`] for more details. Passing `'null'` resets emulation to system defaults. Defaults to `'none'`.
 
 ## context-option-logger
 * langs: js
@@ -817,8 +837,11 @@ An acceptable perceived color difference in the [YIQ color space](https://en.wik
 - %%-context-option-offline-%%
 - %%-context-option-httpcredentials-%%
 - %%-context-option-colorscheme-%%
+- %%-context-option-colorscheme-csharp-%%
 - %%-context-option-reducedMotion-%%
+- %%-context-option-reducedMotion-csharp-%%
 - %%-context-option-forcedColors-%%
+- %%-context-option-forcedColors-csharp-%%
 - %%-context-option-logger-%%
 - %%-context-option-videospath-%%
 - %%-context-option-videosize-%%
diff --git a/packages/playwright-core/src/client/browserContext.ts b/packages/playwright-core/src/client/browserContext.ts
index 8e0693aa2a..2f2ffbb35d 100644
--- a/packages/playwright-core/src/client/browserContext.ts
+++ b/packages/playwright-core/src/client/browserContext.ts
@@ -416,6 +416,9 @@ export async function prepareBrowserContextParams(options: BrowserContextOptions
     storageState: await prepareStorageState(options),
     serviceWorkers: options.serviceWorkers,
     recordHar: prepareRecordHarOptions(options.recordHar),
+    colorScheme: options.colorScheme === null ? 'no-override' : options.colorScheme,
+    reducedMotion: options.reducedMotion === null ? 'no-override' : options.reducedMotion,
+    forcedColors: options.forcedColors === null ? 'no-override' : options.forcedColors,
   };
   if (!contextParams.recordVideo && options.videosPath) {
     contextParams.recordVideo = {
diff --git a/packages/playwright-core/src/client/electron.ts b/packages/playwright-core/src/client/electron.ts
index 106558f727..8f41404a8f 100644
--- a/packages/playwright-core/src/client/electron.ts
+++ b/packages/playwright-core/src/client/electron.ts
@@ -29,10 +29,11 @@ import type { Page } from './page';
 import type { Env, WaitForEventOptions, Headers, BrowserContextOptions } from './types';
 import { Waiter } from './waiter';
 
-type ElectronOptions = Omit<channels.ElectronLaunchOptions, 'env'|'extraHTTPHeaders'|'recordHar'> & {
+type ElectronOptions = Omit<channels.ElectronLaunchOptions, 'env'|'extraHTTPHeaders'|'recordHar'|'colorScheme'> & {
   env?: Env,
   extraHTTPHeaders?: Headers,
   recordHar?: BrowserContextOptions['recordHar'],
+  colorScheme?: 'dark' | 'light' | 'no-preference' | null,
 };
 
 type ElectronAppType = typeof import('electron');
diff --git a/packages/playwright-core/src/client/page.ts b/packages/playwright-core/src/client/page.ts
index f42e8a92f0..1092be9b90 100644
--- a/packages/playwright-core/src/client/page.ts
+++ b/packages/playwright-core/src/client/page.ts
@@ -424,10 +424,10 @@ export class Page extends ChannelOwner<channels.PageChannel> implements api.Page
 
   async emulateMedia(options: { media?: 'screen' | 'print' | null, colorScheme?: 'dark' | 'light' | 'no-preference' | null, reducedMotion?: 'reduce' | 'no-preference' | null, forcedColors?: 'active' | 'none' | null } = {}) {
     await this._channel.emulateMedia({
-      media: options.media === null ? 'null' : options.media,
-      colorScheme: options.colorScheme === null ? 'null' : options.colorScheme,
-      reducedMotion: options.reducedMotion === null ? 'null' : options.reducedMotion,
-      forcedColors: options.forcedColors === null ? 'null' : options.forcedColors,
+      media: options.media === null ? 'no-override' : options.media,
+      colorScheme: options.colorScheme === null ? 'no-override' : options.colorScheme,
+      reducedMotion: options.reducedMotion === null ? 'no-override' : options.reducedMotion,
+      forcedColors: options.forcedColors === null ? 'no-override' : options.forcedColors,
     });
   }
 
diff --git a/packages/playwright-core/src/client/types.ts b/packages/playwright-core/src/client/types.ts
index 517c52c683..3852d00c7f 100644
--- a/packages/playwright-core/src/client/types.ts
+++ b/packages/playwright-core/src/client/types.ts
@@ -47,32 +47,36 @@ export type SetStorageState = {
 export type LifecycleEvent = channels.LifecycleEvent;
 export const kLifecycleEvents: Set<LifecycleEvent> = new Set(['load', 'domcontentloaded', 'networkidle', 'commit']);
 
-export type BrowserContextOptions = Omit<channels.BrowserNewContextOptions, 'viewport' | 'noDefaultViewport' | 'extraHTTPHeaders' | 'storageState' | 'recordHar'> & {
-  viewport?: Size | null,
-  extraHTTPHeaders?: Headers,
-  logger?: Logger,
-  videosPath?: string,
-  videoSize?: Size,
-  storageState?: string | SetStorageState,
+export type BrowserContextOptions = Omit<channels.BrowserNewContextOptions, 'viewport' | 'noDefaultViewport' | 'extraHTTPHeaders' | 'storageState' | 'recordHar' | 'colorScheme' | 'reducedMotion' | 'forcedColors'> & {
+  viewport?: Size | null;
+  extraHTTPHeaders?: Headers;
+  logger?: Logger;
+  videosPath?: string;
+  videoSize?: Size;
+  storageState?: string | SetStorageState;
   har?: {
     path: string;
     fallback?: 'abort'|'continue';
     urlFilter?: string|RegExp;
-  },
+  };
   recordHar?: {
     path: string,
     omitContent?: boolean,
     content?: 'omit' | 'embed' | 'attach',
     mode?: 'full' | 'minimal',
     urlFilter?: string | RegExp,
-  },
+  };
+  colorScheme?: 'dark' | 'light' | 'no-preference' | null;
+  reducedMotion?: 'reduce' | 'no-preference' | null;
+  forcedColors?: 'active' | 'none' | null;
 };
 
 type LaunchOverrides = {
-  ignoreDefaultArgs?: boolean | string[],
-  env?: Env,
-  logger?: Logger,
+  ignoreDefaultArgs?: boolean | string[];
+  env?: Env;
+  logger?: Logger;
 };
+
 type FirefoxUserPrefs = {
   firefoxUserPrefs?: { [key: string]: string | number | boolean },
 };
diff --git a/packages/playwright-core/src/protocol/validator.ts b/packages/playwright-core/src/protocol/validator.ts
index 25c3432a34..4b4333c334 100644
--- a/packages/playwright-core/src/protocol/validator.ts
+++ b/packages/playwright-core/src/protocol/validator.ts
@@ -506,9 +506,9 @@ scheme.BrowserTypeLaunchPersistentContextParams = tObject({
   deviceScaleFactor: tOptional(tNumber),
   isMobile: tOptional(tBoolean),
   hasTouch: tOptional(tBoolean),
-  colorScheme: tOptional(tEnum(['dark', 'light', 'no-preference'])),
-  reducedMotion: tOptional(tEnum(['reduce', 'no-preference'])),
-  forcedColors: tOptional(tEnum(['active', 'none'])),
+  colorScheme: tOptional(tEnum(['dark', 'light', 'no-preference', 'no-override'])),
+  reducedMotion: tOptional(tEnum(['reduce', 'no-preference', 'no-override'])),
+  forcedColors: tOptional(tEnum(['active', 'none', 'no-override'])),
   acceptDownloads: tOptional(tBoolean),
   baseURL: tOptional(tString),
   recordVideo: tOptional(tObject({
@@ -577,9 +577,9 @@ scheme.BrowserNewContextParams = tObject({
   deviceScaleFactor: tOptional(tNumber),
   isMobile: tOptional(tBoolean),
   hasTouch: tOptional(tBoolean),
-  colorScheme: tOptional(tEnum(['dark', 'light', 'no-preference'])),
-  reducedMotion: tOptional(tEnum(['reduce', 'no-preference'])),
-  forcedColors: tOptional(tEnum(['active', 'none'])),
+  colorScheme: tOptional(tEnum(['dark', 'light', 'no-preference', 'no-override'])),
+  reducedMotion: tOptional(tEnum(['reduce', 'no-preference', 'no-override'])),
+  forcedColors: tOptional(tEnum(['active', 'none', 'no-override'])),
   acceptDownloads: tOptional(tBoolean),
   baseURL: tOptional(tString),
   recordVideo: tOptional(tObject({
@@ -637,9 +637,9 @@ scheme.BrowserNewContextForReuseParams = tObject({
   deviceScaleFactor: tOptional(tNumber),
   isMobile: tOptional(tBoolean),
   hasTouch: tOptional(tBoolean),
-  colorScheme: tOptional(tEnum(['dark', 'light', 'no-preference'])),
-  reducedMotion: tOptional(tEnum(['reduce', 'no-preference'])),
-  forcedColors: tOptional(tEnum(['active', 'none'])),
+  colorScheme: tOptional(tEnum(['dark', 'light', 'no-preference', 'no-override'])),
+  reducedMotion: tOptional(tEnum(['reduce', 'no-preference', 'no-override'])),
+  forcedColors: tOptional(tEnum(['active', 'none', 'no-override'])),
   acceptDownloads: tOptional(tBoolean),
   baseURL: tOptional(tString),
   recordVideo: tOptional(tObject({
@@ -932,10 +932,10 @@ scheme.PageCloseParams = tObject({
 });
 scheme.PageCloseResult = tOptional(tObject({}));
 scheme.PageEmulateMediaParams = tObject({
-  media: tOptional(tEnum(['screen', 'print', 'null'])),
-  colorScheme: tOptional(tEnum(['dark', 'light', 'no-preference', 'null'])),
-  reducedMotion: tOptional(tEnum(['reduce', 'no-preference', 'null'])),
-  forcedColors: tOptional(tEnum(['active', 'none', 'null'])),
+  media: tOptional(tEnum(['screen', 'print', 'no-override'])),
+  colorScheme: tOptional(tEnum(['dark', 'light', 'no-preference', 'no-override'])),
+  reducedMotion: tOptional(tEnum(['reduce', 'no-preference', 'no-override'])),
+  forcedColors: tOptional(tEnum(['active', 'none', 'no-override'])),
 });
 scheme.PageEmulateMediaResult = tOptional(tObject({}));
 scheme.PageExposeBindingParams = tObject({
@@ -2125,7 +2125,7 @@ scheme.ElectronLaunchParams = tObject({
   timeout: tOptional(tNumber),
   acceptDownloads: tOptional(tBoolean),
   bypassCSP: tOptional(tBoolean),
-  colorScheme: tOptional(tEnum(['dark', 'light', 'no-preference'])),
+  colorScheme: tOptional(tEnum(['dark', 'light', 'no-preference', 'no-override'])),
   extraHTTPHeaders: tOptional(tArray(tType('NameValue'))),
   geolocation: tOptional(tObject({
     longitude: tNumber,
@@ -2347,9 +2347,9 @@ scheme.AndroidDeviceLaunchBrowserParams = tObject({
   deviceScaleFactor: tOptional(tNumber),
   isMobile: tOptional(tBoolean),
   hasTouch: tOptional(tBoolean),
-  colorScheme: tOptional(tEnum(['dark', 'light', 'no-preference'])),
-  reducedMotion: tOptional(tEnum(['reduce', 'no-preference'])),
-  forcedColors: tOptional(tEnum(['active', 'none'])),
+  colorScheme: tOptional(tEnum(['dark', 'light', 'no-preference', 'no-override'])),
+  reducedMotion: tOptional(tEnum(['reduce', 'no-preference', 'no-override'])),
+  forcedColors: tOptional(tEnum(['active', 'none', 'no-override'])),
   acceptDownloads: tOptional(tBoolean),
   baseURL: tOptional(tString),
   recordVideo: tOptional(tObject({
diff --git a/packages/playwright-core/src/server/chromium/crPage.ts b/packages/playwright-core/src/server/chromium/crPage.ts
index 60890a2200..e66868b2cd 100644
--- a/packages/playwright-core/src/server/chromium/crPage.ts
+++ b/packages/playwright-core/src/server/chromium/crPage.ts
@@ -1064,16 +1064,17 @@ class FrameSession {
 
   async _updateEmulateMedia(): Promise<void> {
     const emulatedMedia = this._page.emulatedMedia();
-    const colorScheme = emulatedMedia.colorScheme === null ? '' : emulatedMedia.colorScheme;
-    const reducedMotion = emulatedMedia.reducedMotion === null ? '' : emulatedMedia.reducedMotion;
-    const forcedColors = emulatedMedia.forcedColors === null ? '' : emulatedMedia.forcedColors;
+    // Empty string disables the override.
+    const media = emulatedMedia.media === 'no-override' ? '' : emulatedMedia.media;
+    const colorScheme = emulatedMedia.colorScheme === 'no-override' ? '' : emulatedMedia.colorScheme;
+    const reducedMotion = emulatedMedia.reducedMotion === 'no-override' ? '' : emulatedMedia.reducedMotion;
+    const forcedColors = emulatedMedia.forcedColors === 'no-override' ? '' : emulatedMedia.forcedColors;
     const features = [
       { name: 'prefers-color-scheme', value: colorScheme },
       { name: 'prefers-reduced-motion', value: reducedMotion },
       { name: 'forced-colors', value: forcedColors },
     ];
-    // Empty string disables the override.
-    await this._client.send('Emulation.setEmulatedMedia', { media: emulatedMedia.media || '', features });
+    await this._client.send('Emulation.setEmulatedMedia', { media, features });
   }
 
   async _updateUserAgent(): Promise<void> {
diff --git a/packages/playwright-core/src/server/dispatchers/pageDispatcher.ts b/packages/playwright-core/src/server/dispatchers/pageDispatcher.ts
index 20a390c351..651920e38d 100644
--- a/packages/playwright-core/src/server/dispatchers/pageDispatcher.ts
+++ b/packages/playwright-core/src/server/dispatchers/pageDispatcher.ts
@@ -138,10 +138,10 @@ export class PageDispatcher extends Dispatcher<Page, channels.PageChannel, Brows
 
   async emulateMedia(params: channels.PageEmulateMediaParams, metadata: CallMetadata): Promise<void> {
     await this._page.emulateMedia({
-      media: params.media === 'null' ? null : params.media,
-      colorScheme: params.colorScheme === 'null' ? null : params.colorScheme,
-      reducedMotion: params.reducedMotion === 'null' ? null : params.reducedMotion,
-      forcedColors: params.forcedColors === 'null' ? null : params.forcedColors,
+      media: params.media,
+      colorScheme: params.colorScheme,
+      reducedMotion: params.reducedMotion,
+      forcedColors: params.forcedColors,
     });
   }
 
diff --git a/packages/playwright-core/src/server/firefox/ffBrowser.ts b/packages/playwright-core/src/server/firefox/ffBrowser.ts
index 3d454ca935..5a65732d8d 100644
--- a/packages/playwright-core/src/server/firefox/ffBrowser.ts
+++ b/packages/playwright-core/src/server/firefox/ffBrowser.ts
@@ -204,18 +204,24 @@ export class FFBrowserContext extends BrowserContext {
       promises.push(this.setGeolocation(this._options.geolocation));
     if (this._options.offline)
       promises.push(this.setOffline(this._options.offline));
-    promises.push(this._browser._connection.send('Browser.setColorScheme', {
-      browserContextId,
-      colorScheme: this._options.colorScheme !== undefined  ? this._options.colorScheme : 'light',
-    }));
-    promises.push(this._browser._connection.send('Browser.setReducedMotion', {
-      browserContextId,
-      reducedMotion: this._options.reducedMotion !== undefined  ? this._options.reducedMotion : 'no-preference',
-    }));
-    promises.push(this._browser._connection.send('Browser.setForcedColors', {
-      browserContextId,
-      forcedColors: this._options.forcedColors !== undefined  ? this._options.forcedColors : 'none',
-    }));
+    if (this._options.colorScheme !== 'no-override') {
+      promises.push(this._browser._connection.send('Browser.setColorScheme', {
+        browserContextId,
+        colorScheme: this._options.colorScheme !== undefined  ? this._options.colorScheme : 'light',
+      }));
+    }
+    if (this._options.reducedMotion !== 'no-override') {
+      promises.push(this._browser._connection.send('Browser.setReducedMotion', {
+        browserContextId,
+        reducedMotion: this._options.reducedMotion !== undefined  ? this._options.reducedMotion : 'no-preference',
+      }));
+    }
+    if (this._options.forcedColors !== 'no-override') {
+      promises.push(this._browser._connection.send('Browser.setForcedColors', {
+        browserContextId,
+        forcedColors: this._options.forcedColors !== undefined  ? this._options.forcedColors : 'none',
+      }));
+    }
     if (this._options.recordVideo) {
       promises.push(this._ensureVideosPath().then(() => {
         return this._browser._connection.send('Browser.setVideoRecordingOptions', {
diff --git a/packages/playwright-core/src/server/firefox/ffPage.ts b/packages/playwright-core/src/server/firefox/ffPage.ts
index b3d67e2bcc..ae03182af8 100644
--- a/packages/playwright-core/src/server/firefox/ffPage.ts
+++ b/packages/playwright-core/src/server/firefox/ffPage.ts
@@ -371,12 +371,12 @@ export class FFPage implements PageDelegate {
 
   async updateEmulateMedia(): Promise<void> {
     const emulatedMedia = this._page.emulatedMedia();
-    const colorScheme = emulatedMedia.colorScheme ?? undefined;
-    const reducedMotion = emulatedMedia.reducedMotion ?? undefined;
-    const forcedColors = emulatedMedia.forcedColors ?? undefined;
+    const colorScheme = emulatedMedia.colorScheme === 'no-override' ? undefined : emulatedMedia.colorScheme;
+    const reducedMotion = emulatedMedia.reducedMotion === 'no-override' ? undefined : emulatedMedia.reducedMotion;
+    const forcedColors = emulatedMedia.forcedColors === 'no-override' ? undefined : emulatedMedia.forcedColors;
     await this._session.send('Page.setEmulatedMedia', {
       // Empty string means reset.
-      type: emulatedMedia.media === null ? '' : emulatedMedia.media,
+      type: emulatedMedia.media === 'no-override' ? '' : emulatedMedia.media,
       colorScheme,
       reducedMotion,
       forcedColors,
diff --git a/packages/playwright-core/src/server/page.ts b/packages/playwright-core/src/server/page.ts
index b8c7ebbe3e..e66162c7a2 100644
--- a/packages/playwright-core/src/server/page.ts
+++ b/packages/playwright-core/src/server/page.ts
@@ -101,10 +101,10 @@ export interface PageDelegate {
 type EmulatedSize = { screen: types.Size, viewport: types.Size };
 
 type EmulatedMedia = {
-  media: types.MediaType | null;
-  colorScheme: types.ColorScheme | null;
-  reducedMotion: types.ReducedMotion | null;
-  forcedColors: types.ForcedColors | null;
+  media: types.MediaType;
+  colorScheme: types.ColorScheme;
+  reducedMotion: types.ReducedMotion;
+  forcedColors: types.ForcedColors;
 };
 
 type ExpectScreenshotOptions = {
@@ -442,7 +442,7 @@ export class Page extends SdkObject {
   emulatedMedia(): EmulatedMedia {
     const contextOptions = this._browserContext._options;
     return {
-      media: this._emulatedMedia.media || null,
+      media: this._emulatedMedia.media || 'no-override',
       colorScheme: this._emulatedMedia.colorScheme !== undefined ? this._emulatedMedia.colorScheme : contextOptions.colorScheme ?? 'light',
       reducedMotion: this._emulatedMedia.reducedMotion !== undefined ? this._emulatedMedia.reducedMotion : contextOptions.reducedMotion ?? 'no-preference',
       forcedColors: this._emulatedMedia.forcedColors !== undefined ? this._emulatedMedia.forcedColors : contextOptions.forcedColors ?? 'none',
diff --git a/packages/playwright-core/src/server/recorder/recorderApp.ts b/packages/playwright-core/src/server/recorder/recorderApp.ts
index 9add17d1c2..5d6f29398d 100644
--- a/packages/playwright-core/src/server/recorder/recorderApp.ts
+++ b/packages/playwright-core/src/server/recorder/recorderApp.ts
@@ -125,6 +125,7 @@ export class RecorderApp extends EventEmitter implements IRecorderApp {
       channel: findChromiumChannel(sdkLanguage),
       args,
       noDefaultViewport: true,
+      colorScheme: 'no-override',
       ignoreDefaultArgs: ['--enable-automation'],
       headless: !!process.env.PWTEST_CLI_HEADLESS || (isUnderTest() && !headed),
       useWebSocket: !!process.env.PWTEST_RECORDER_PORT,
diff --git a/packages/playwright-core/src/server/trace/viewer/traceViewer.ts b/packages/playwright-core/src/server/trace/viewer/traceViewer.ts
index a6ba863633..ff924da5a1 100644
--- a/packages/playwright-core/src/server/trace/viewer/traceViewer.ts
+++ b/packages/playwright-core/src/server/trace/viewer/traceViewer.ts
@@ -68,6 +68,7 @@ export async function showTraceViewer(traceUrls: string[], browserName: string,
     noDefaultViewport: true,
     ignoreDefaultArgs: ['--enable-automation'],
     headless,
+    colorScheme: 'no-override',
     useWebSocket: isUnderTest()
   });
 
diff --git a/packages/playwright-core/src/server/types.ts b/packages/playwright-core/src/server/types.ts
index 661244a9c9..319b774839 100644
--- a/packages/playwright-core/src/server/types.ts
+++ b/packages/playwright-core/src/server/types.ts
@@ -77,13 +77,13 @@ export type FilePayload = {
   buffer: string,
 };
 
-export type MediaType = 'screen' | 'print';
+export type MediaType = 'screen' | 'print' | 'no-override';
 
-export type ColorScheme = 'dark' | 'light' | 'no-preference';
+export type ColorScheme = 'dark' | 'light' | 'no-preference' | 'no-override';
 
-export type ReducedMotion = 'no-preference' | 'reduce';
+export type ReducedMotion = 'no-preference' | 'reduce' | 'no-override';
 
-export type ForcedColors = 'active' | 'none';
+export type ForcedColors = 'active' | 'none' | 'no-override';
 
 export type DeviceDescriptor = {
   userAgent: string,
diff --git a/packages/playwright-core/src/server/webkit/wkPage.ts b/packages/playwright-core/src/server/webkit/wkPage.ts
index f3939b2993..e367a5dc69 100644
--- a/packages/playwright-core/src/server/webkit/wkPage.ts
+++ b/packages/playwright-core/src/server/webkit/wkPage.ts
@@ -627,25 +627,28 @@ export class WKPage implements PageDelegate {
     await this._page._onFileChooserOpened(handle);
   }
 
-  private static async _setEmulateMedia(session: WKSession, mediaType: types.MediaType | null, colorScheme: types.ColorScheme | null, reducedMotion: types.ReducedMotion | null, forcedColors: types.ForcedColors | null): Promise<void> {
+  private static async _setEmulateMedia(session: WKSession, mediaType: types.MediaType, colorScheme: types.ColorScheme, reducedMotion: types.ReducedMotion, forcedColors: types.ForcedColors): Promise<void> {
     const promises = [];
-    promises.push(session.send('Page.setEmulatedMedia', { media: mediaType || '' }));
+    promises.push(session.send('Page.setEmulatedMedia', { media: mediaType === 'no-override' ? '' : mediaType }));
     let appearance: any = undefined;
     switch (colorScheme) {
       case 'light': appearance = 'Light'; break;
       case 'dark': appearance = 'Dark'; break;
+      case 'no-override': appearance = undefined; break;
     }
     promises.push(session.send('Page.setForcedAppearance', { appearance }));
     let reducedMotionWk: any = undefined;
     switch (reducedMotion) {
       case 'reduce': reducedMotionWk = 'Reduce'; break;
       case 'no-preference': reducedMotionWk = 'NoPreference'; break;
+      case 'no-override': reducedMotionWk = undefined; break;
     }
     promises.push(session.send('Page.setForcedReducedMotion', { reducedMotion: reducedMotionWk }));
     let forcedColorsWk: any = undefined;
     switch (forcedColors) {
       case 'active': forcedColorsWk = 'Active'; break;
       case 'none': forcedColorsWk = 'None'; break;
+      case 'no-override': forcedColorsWk = undefined; break;
     }
     promises.push(session.send('Page.setForcedColors', { forcedColors: forcedColorsWk }));
     await Promise.all(promises);
diff --git a/packages/playwright-core/types/types.d.ts b/packages/playwright-core/types/types.d.ts
index 17f32c8b7a..c850dcc02d 100644
--- a/packages/playwright-core/types/types.d.ts
+++ b/packages/playwright-core/types/types.d.ts
@@ -11337,10 +11337,10 @@ export interface BrowserType<Unused = {}> {
 
     /**
      * Emulates `'prefers-colors-scheme'` media feature, supported values are `'light'`, `'dark'`, `'no-preference'`. See
-     * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Defaults
-     * to `'light'`.
+     * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Passing
+     * `null` resets emulation to system defaults. Defaults to `'light'`.
      */
-    colorScheme?: "light"|"dark"|"no-preference";
+    colorScheme?: null|"light"|"dark"|"no-preference";
 
     /**
      * Specify device scale factor (can be thought of as dpr). Defaults to `1`.
@@ -11379,10 +11379,10 @@ export interface BrowserType<Unused = {}> {
 
     /**
      * Emulates `'forced-colors'` media feature, supported values are `'active'`, `'none'`. See
-     * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Defaults
-     * to `'none'`.
+     * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Passing
+     * `null` resets emulation to system defaults. Defaults to `'none'`.
      */
-    forcedColors?: "active"|"none";
+    forcedColors?: null|"active"|"none";
 
     geolocation?: {
       /**
@@ -11581,10 +11581,10 @@ export interface BrowserType<Unused = {}> {
 
     /**
      * Emulates `'prefers-reduced-motion'` media feature, supported values are `'reduce'`, `'no-preference'`. See
-     * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Defaults
-     * to `'no-preference'`.
+     * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Passing
+     * `null` resets emulation to system defaults. Defaults to `'no-preference'`.
      */
-    reducedMotion?: "reduce"|"no-preference";
+    reducedMotion?: null|"reduce"|"no-preference";
 
     /**
      * Emulates consistent window screen size available inside web page via `window.screen`. Is only used when the `viewport`
@@ -12765,10 +12765,10 @@ export interface AndroidDevice {
 
     /**
      * Emulates `'prefers-colors-scheme'` media feature, supported values are `'light'`, `'dark'`, `'no-preference'`. See
-     * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Defaults
-     * to `'light'`.
+     * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Passing
+     * `null` resets emulation to system defaults. Defaults to `'light'`.
      */
-    colorScheme?: "light"|"dark"|"no-preference";
+    colorScheme?: null|"light"|"dark"|"no-preference";
 
     /**
      * Optional package name to launch instead of default Chrome for Android.
@@ -12787,10 +12787,10 @@ export interface AndroidDevice {
 
     /**
      * Emulates `'forced-colors'` media feature, supported values are `'active'`, `'none'`. See
-     * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Defaults
-     * to `'none'`.
+     * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Passing
+     * `null` resets emulation to system defaults. Defaults to `'none'`.
      */
-    forcedColors?: "active"|"none";
+    forcedColors?: null|"active"|"none";
 
     geolocation?: {
       /**
@@ -12934,10 +12934,10 @@ export interface AndroidDevice {
 
     /**
      * Emulates `'prefers-reduced-motion'` media feature, supported values are `'reduce'`, `'no-preference'`. See
-     * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Defaults
-     * to `'no-preference'`.
+     * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Passing
+     * `null` resets emulation to system defaults. Defaults to `'no-preference'`.
      */
-    reducedMotion?: "reduce"|"no-preference";
+    reducedMotion?: null|"reduce"|"no-preference";
 
     /**
      * Emulates consistent window screen size available inside web page via `window.screen`. Is only used when the `viewport`
@@ -14552,10 +14552,10 @@ export interface Browser extends EventEmitter {
 
     /**
      * Emulates `'prefers-colors-scheme'` media feature, supported values are `'light'`, `'dark'`, `'no-preference'`. See
-     * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Defaults
-     * to `'light'`.
+     * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Passing
+     * `null` resets emulation to system defaults. Defaults to `'light'`.
      */
-    colorScheme?: "light"|"dark"|"no-preference";
+    colorScheme?: null|"light"|"dark"|"no-preference";
 
     /**
      * Specify device scale factor (can be thought of as dpr). Defaults to `1`.
@@ -14569,10 +14569,10 @@ export interface Browser extends EventEmitter {
 
     /**
      * Emulates `'forced-colors'` media feature, supported values are `'active'`, `'none'`. See
-     * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Defaults
-     * to `'none'`.
+     * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Passing
+     * `null` resets emulation to system defaults. Defaults to `'none'`.
      */
-    forcedColors?: "active"|"none";
+    forcedColors?: null|"active"|"none";
 
     geolocation?: {
       /**
@@ -14746,10 +14746,10 @@ export interface Browser extends EventEmitter {
 
     /**
      * Emulates `'prefers-reduced-motion'` media feature, supported values are `'reduce'`, `'no-preference'`. See
-     * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Defaults
-     * to `'no-preference'`.
+     * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Passing
+     * `null` resets emulation to system defaults. Defaults to `'no-preference'`.
      */
-    reducedMotion?: "reduce"|"no-preference";
+    reducedMotion?: null|"reduce"|"no-preference";
 
     /**
      * Emulates consistent window screen size available inside web page via `window.screen`. Is only used when the `viewport`
@@ -15400,10 +15400,10 @@ export interface Electron {
 
     /**
      * Emulates `'prefers-colors-scheme'` media feature, supported values are `'light'`, `'dark'`, `'no-preference'`. See
-     * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Defaults
-     * to `'light'`.
+     * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Passing
+     * `null` resets emulation to system defaults. Defaults to `'light'`.
      */
-    colorScheme?: "light"|"dark"|"no-preference";
+    colorScheme?: null|"light"|"dark"|"no-preference";
 
     /**
      * Current working directory to launch application from.
@@ -17421,10 +17421,10 @@ export interface BrowserContextOptions {
 
   /**
    * Emulates `'prefers-colors-scheme'` media feature, supported values are `'light'`, `'dark'`, `'no-preference'`. See
-   * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Defaults
-   * to `'light'`.
+   * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Passing
+   * `null` resets emulation to system defaults. Defaults to `'light'`.
    */
-  colorScheme?: "light"|"dark"|"no-preference";
+  colorScheme?: null|"light"|"dark"|"no-preference";
 
   /**
    * Specify device scale factor (can be thought of as dpr). Defaults to `1`.
@@ -17438,10 +17438,10 @@ export interface BrowserContextOptions {
 
   /**
    * Emulates `'forced-colors'` media feature, supported values are `'active'`, `'none'`. See
-   * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Defaults
-   * to `'none'`.
+   * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Passing
+   * `null` resets emulation to system defaults. Defaults to `'none'`.
    */
-  forcedColors?: "active"|"none";
+  forcedColors?: null|"active"|"none";
 
   geolocation?: Geolocation;
 
@@ -17596,10 +17596,10 @@ export interface BrowserContextOptions {
 
   /**
    * Emulates `'prefers-reduced-motion'` media feature, supported values are `'reduce'`, `'no-preference'`. See
-   * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Defaults
-   * to `'no-preference'`.
+   * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Passing
+   * `null` resets emulation to system defaults. Defaults to `'no-preference'`.
    */
-  reducedMotion?: "reduce"|"no-preference";
+  reducedMotion?: null|"reduce"|"no-preference";
 
   /**
    * Emulates consistent window screen size available inside web page via `window.screen`. Is only used when the `viewport`
diff --git a/packages/playwright-test/types/test.d.ts b/packages/playwright-test/types/test.d.ts
index 5d651ac92b..dd9e24f8dd 100644
--- a/packages/playwright-test/types/test.d.ts
+++ b/packages/playwright-test/types/test.d.ts
@@ -2857,8 +2857,8 @@ export interface PlaywrightTestOptions {
   bypassCSP: boolean | undefined;
   /**
    * Emulates `'prefers-colors-scheme'` media feature, supported values are `'light'`, `'dark'`, `'no-preference'`. See
-   * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Defaults
-   * to `'light'`.
+   * [page.emulateMedia([options])](https://playwright.dev/docs/api/class-page#page-emulate-media) for more details. Passing
+   * `null` resets emulation to system defaults. Defaults to `'light'`.
    */
   colorScheme: ColorScheme | undefined;
   /**
diff --git a/packages/protocol/src/channels.ts b/packages/protocol/src/channels.ts
index a7d6c5881c..77f76577f6 100644
--- a/packages/protocol/src/channels.ts
+++ b/packages/protocol/src/channels.ts
@@ -892,9 +892,9 @@ export type BrowserTypeLaunchPersistentContextParams = {
   deviceScaleFactor?: number,
   isMobile?: boolean,
   hasTouch?: boolean,
-  colorScheme?: 'dark' | 'light' | 'no-preference',
-  reducedMotion?: 'reduce' | 'no-preference',
-  forcedColors?: 'active' | 'none',
+  colorScheme?: 'dark' | 'light' | 'no-preference' | 'no-override',
+  reducedMotion?: 'reduce' | 'no-preference' | 'no-override',
+  forcedColors?: 'active' | 'none' | 'no-override',
   acceptDownloads?: boolean,
   baseURL?: string,
   recordVideo?: {
@@ -962,9 +962,9 @@ export type BrowserTypeLaunchPersistentContextOptions = {
   deviceScaleFactor?: number,
   isMobile?: boolean,
   hasTouch?: boolean,
-  colorScheme?: 'dark' | 'light' | 'no-preference',
-  reducedMotion?: 'reduce' | 'no-preference',
-  forcedColors?: 'active' | 'none',
+  colorScheme?: 'dark' | 'light' | 'no-preference' | 'no-override',
+  reducedMotion?: 'reduce' | 'no-preference' | 'no-override',
+  forcedColors?: 'active' | 'none' | 'no-override',
   acceptDownloads?: boolean,
   baseURL?: string,
   recordVideo?: {
@@ -1057,9 +1057,9 @@ export type BrowserNewContextParams = {
   deviceScaleFactor?: number,
   isMobile?: boolean,
   hasTouch?: boolean,
-  colorScheme?: 'dark' | 'light' | 'no-preference',
-  reducedMotion?: 'reduce' | 'no-preference',
-  forcedColors?: 'active' | 'none',
+  colorScheme?: 'dark' | 'light' | 'no-preference' | 'no-override',
+  reducedMotion?: 'reduce' | 'no-preference' | 'no-override',
+  forcedColors?: 'active' | 'none' | 'no-override',
   acceptDownloads?: boolean,
   baseURL?: string,
   recordVideo?: {
@@ -1114,9 +1114,9 @@ export type BrowserNewContextOptions = {
   deviceScaleFactor?: number,
   isMobile?: boolean,
   hasTouch?: boolean,
-  colorScheme?: 'dark' | 'light' | 'no-preference',
-  reducedMotion?: 'reduce' | 'no-preference',
-  forcedColors?: 'active' | 'none',
+  colorScheme?: 'dark' | 'light' | 'no-preference' | 'no-override',
+  reducedMotion?: 'reduce' | 'no-preference' | 'no-override',
+  forcedColors?: 'active' | 'none' | 'no-override',
   acceptDownloads?: boolean,
   baseURL?: string,
   recordVideo?: {
@@ -1174,9 +1174,9 @@ export type BrowserNewContextForReuseParams = {
   deviceScaleFactor?: number,
   isMobile?: boolean,
   hasTouch?: boolean,
-  colorScheme?: 'dark' | 'light' | 'no-preference',
-  reducedMotion?: 'reduce' | 'no-preference',
-  forcedColors?: 'active' | 'none',
+  colorScheme?: 'dark' | 'light' | 'no-preference' | 'no-override',
+  reducedMotion?: 'reduce' | 'no-preference' | 'no-override',
+  forcedColors?: 'active' | 'none' | 'no-override',
   acceptDownloads?: boolean,
   baseURL?: string,
   recordVideo?: {
@@ -1231,9 +1231,9 @@ export type BrowserNewContextForReuseOptions = {
   deviceScaleFactor?: number,
   isMobile?: boolean,
   hasTouch?: boolean,
-  colorScheme?: 'dark' | 'light' | 'no-preference',
-  reducedMotion?: 'reduce' | 'no-preference',
-  forcedColors?: 'active' | 'none',
+  colorScheme?: 'dark' | 'light' | 'no-preference' | 'no-override',
+  reducedMotion?: 'reduce' | 'no-preference' | 'no-override',
+  forcedColors?: 'active' | 'none' | 'no-override',
   acceptDownloads?: boolean,
   baseURL?: string,
   recordVideo?: {
@@ -1740,16 +1740,16 @@ export type PageCloseOptions = {
 };
 export type PageCloseResult = void;
 export type PageEmulateMediaParams = {
-  media?: 'screen' | 'print' | 'null',
-  colorScheme?: 'dark' | 'light' | 'no-preference' | 'null',
-  reducedMotion?: 'reduce' | 'no-preference' | 'null',
-  forcedColors?: 'active' | 'none' | 'null',
+  media?: 'screen' | 'print' | 'no-override',
+  colorScheme?: 'dark' | 'light' | 'no-preference' | 'no-override',
+  reducedMotion?: 'reduce' | 'no-preference' | 'no-override',
+  forcedColors?: 'active' | 'none' | 'no-override',
 };
 export type PageEmulateMediaOptions = {
-  media?: 'screen' | 'print' | 'null',
-  colorScheme?: 'dark' | 'light' | 'no-preference' | 'null',
-  reducedMotion?: 'reduce' | 'no-preference' | 'null',
-  forcedColors?: 'active' | 'none' | 'null',
+  media?: 'screen' | 'print' | 'no-override',
+  colorScheme?: 'dark' | 'light' | 'no-preference' | 'no-override',
+  reducedMotion?: 'reduce' | 'no-preference' | 'no-override',
+  forcedColors?: 'active' | 'none' | 'no-override',
 };
 export type PageEmulateMediaResult = void;
 export type PageExposeBindingParams = {
@@ -3856,7 +3856,7 @@ export type ElectronLaunchParams = {
   timeout?: number,
   acceptDownloads?: boolean,
   bypassCSP?: boolean,
-  colorScheme?: 'dark' | 'light' | 'no-preference',
+  colorScheme?: 'dark' | 'light' | 'no-preference' | 'no-override',
   extraHTTPHeaders?: NameValue[],
   geolocation?: {
     longitude: number,
@@ -3889,7 +3889,7 @@ export type ElectronLaunchOptions = {
   timeout?: number,
   acceptDownloads?: boolean,
   bypassCSP?: boolean,
-  colorScheme?: 'dark' | 'light' | 'no-preference',
+  colorScheme?: 'dark' | 'light' | 'no-preference' | 'no-override',
   extraHTTPHeaders?: NameValue[],
   geolocation?: {
     longitude: number,
@@ -4272,9 +4272,9 @@ export type AndroidDeviceLaunchBrowserParams = {
   deviceScaleFactor?: number,
   isMobile?: boolean,
   hasTouch?: boolean,
-  colorScheme?: 'dark' | 'light' | 'no-preference',
-  reducedMotion?: 'reduce' | 'no-preference',
-  forcedColors?: 'active' | 'none',
+  colorScheme?: 'dark' | 'light' | 'no-preference' | 'no-override',
+  reducedMotion?: 'reduce' | 'no-preference' | 'no-override',
+  forcedColors?: 'active' | 'none' | 'no-override',
   acceptDownloads?: boolean,
   baseURL?: string,
   recordVideo?: {
@@ -4326,9 +4326,9 @@ export type AndroidDeviceLaunchBrowserOptions = {
   deviceScaleFactor?: number,
   isMobile?: boolean,
   hasTouch?: boolean,
-  colorScheme?: 'dark' | 'light' | 'no-preference',
-  reducedMotion?: 'reduce' | 'no-preference',
-  forcedColors?: 'active' | 'none',
+  colorScheme?: 'dark' | 'light' | 'no-preference' | 'no-override',
+  reducedMotion?: 'reduce' | 'no-preference' | 'no-override',
+  forcedColors?: 'active' | 'none' | 'no-override',
   acceptDownloads?: boolean,
   baseURL?: string,
   recordVideo?: {
diff --git a/packages/protocol/src/protocol.yml b/packages/protocol/src/protocol.yml
index 78f94925f2..767c451474 100644
--- a/packages/protocol/src/protocol.yml
+++ b/packages/protocol/src/protocol.yml
@@ -445,16 +445,19 @@ ContextOptions:
       - dark
       - light
       - no-preference
+      - no-override
     reducedMotion:
       type: enum?
       literals:
       - reduce
       - no-preference
+      - no-override
     forcedColors:
       type: enum?
       literals:
       - active
       - none
+      - no-override
     acceptDownloads: boolean?
     baseURL: string?
     recordVideo:
@@ -1173,30 +1176,26 @@ Page:
           literals:
           - screen
           - print
-          # Reset emulated value to the system default.
-          - null
+          - no-override
         colorScheme:
           type: enum?
           literals:
           - dark
           - light
           - no-preference
-          # Reset emulated value to the system default.
-          - null
+          - no-override
         reducedMotion:
           type: enum?
           literals:
           - reduce
           - no-preference
-          # Reset emulated value to the system default.
-          - null
+          - no-override
         forcedColors:
           type: enum?
           literals:
           - active
           - none
-          # Reset emulated value to the system default.
-          - null
+          - no-override
 
     exposeBinding:
       parameters:
@@ -2974,6 +2973,7 @@ Electron:
           - dark
           - light
           - no-preference
+          - no-override
         extraHTTPHeaders:
           type: array?
           items: NameValue
diff --git a/tests/page/page-emulate-media.spec.ts b/tests/page/page-emulate-media.spec.ts
index 1f8bcca841..85caa1dc8f 100644
--- a/tests/page/page-emulate-media.spec.ts
+++ b/tests/page/page-emulate-media.spec.ts
@@ -35,7 +35,7 @@ it('should throw in case of bad media argument', async ({ page }) => {
   let error = null;
   // @ts-expect-error 'bad' is not a valid media type
   await page.emulateMedia({ media: 'bad' }).catch(e => error = e);
-  expect(error.message).toContain('media: expected one of (screen|print|null)');
+  expect(error.message).toContain('media: expected one of (screen|print|no-override)');
 });
 
 it('should emulate colorScheme should work @smoke', async ({ page }) => {
@@ -64,7 +64,7 @@ it('should throw in case of bad colorScheme argument', async ({ page }) => {
   let error = null;
   // @ts-expect-error 'bad' is not a valid media type
   await page.emulateMedia({ colorScheme: 'bad' }).catch(e => error = e);
-  expect(error.message).toContain('colorScheme: expected one of (dark|light|no-preference|null)');
+  expect(error.message).toContain('colorScheme: expected one of (dark|light|no-preference|no-override)');
 });
 
 it('should work during navigation', async ({ page, server }) => {