diff --git a/packages/playwright-core/src/server/trace/viewer/traceViewer.ts b/packages/playwright-core/src/server/trace/viewer/traceViewer.ts
index a49148e061..b8dc3e5314 100644
--- a/packages/playwright-core/src/server/trace/viewer/traceViewer.ts
+++ b/packages/playwright-core/src/server/trace/viewer/traceViewer.ts
@@ -163,6 +163,7 @@ export async function openTraceViewerApp(url: string, browserName: string, optio
       ...options?.persistentContextOptions,
       useWebSocket: isUnderTest(),
       headless: !!options?.headless,
+      colorScheme: isUnderTest() ? 'light' : undefined,
     },
   });
 
diff --git a/tests/config/proxy.ts b/tests/config/proxy.ts
index 1853196e6e..0e71e47790 100644
--- a/tests/config/proxy.ts
+++ b/tests/config/proxy.ts
@@ -21,6 +21,7 @@ import net from 'net';
 import type { SocksSocketClosedPayload, SocksSocketDataPayload, SocksSocketRequestedPayload } from '../../packages/playwright-core/src/common/socksProxy';
 import { SocksProxy } from '../../packages/playwright-core/lib/common/socksProxy';
 
+// Certain browsers perform telemetry requests which we want to ignore.
 const kConnectHostsToIgnore = new Set([
   'www.bing.com:443',
 ]);
diff --git a/tests/library/browsertype-connect.spec.ts b/tests/library/browsertype-connect.spec.ts
index 9cf103ee2f..ed0234224e 100644
--- a/tests/library/browsertype-connect.spec.ts
+++ b/tests/library/browsertype-connect.spec.ts
@@ -169,9 +169,9 @@ for (const kind of ['launchServer', 'run-server'] as const) {
       await browser.close();
     });
 
-    test('should ignore page.pause when headed', async ({ connect, startRemoteServer, browserType, headless }) => {
-      test.skip(headless, 'This test is only relevant in headed mode');
-      const originalHeadlessValue = (browserType as any)._defaultLaunchOptions.headless;
+    test('should ignore page.pause when headed', async ({ connect, startRemoteServer, browserType, channel }) => {
+      test.skip(channel === 'chromium-headless-shell', 'This test is only relevant in headed mode');
+      const headless = (browserType as any)._defaultLaunchOptions.headless;
       (browserType as any)._defaultLaunchOptions.headless = false;
       const remoteServer = await startRemoteServer(kind);
       const browser = await connect(remoteServer.wsEndpoint());
@@ -179,7 +179,7 @@ for (const kind of ['launchServer', 'run-server'] as const) {
       const page = await browserContext.newPage();
       await page.pause();
       await browser.close();
-      (browserType as any)._defaultLaunchOptions.headless = originalHeadlessValue;
+      (browserType as any)._defaultLaunchOptions.headless = headless;
     });
 
     test('should be able to visit ipv6 through localhost', async ({ connect, startRemoteServer, ipV6ServerPort }) => {
diff --git a/tests/library/channels.spec.ts b/tests/library/channels.spec.ts
index 5d9d0c78b3..314a55a3e5 100644
--- a/tests/library/channels.spec.ts
+++ b/tests/library/channels.spec.ts
@@ -262,7 +262,7 @@ it('should work with the domain module', async ({ browserType, server, browserNa
   if (browserName === 'firefox')
     expect(message).toBe('CLOSE_ABNORMAL');
   else
-    expect(message).toContain(channel.includes('msedge') ? '' : ': 400');
+    expect(message).toContain(channel?.includes('msedge') ? '' : ': 400');
 
   await browser.close();
 
diff --git a/tests/library/web-socket.spec.ts b/tests/library/web-socket.spec.ts
index c3d48ad267..94b8ff1b2b 100644
--- a/tests/library/web-socket.spec.ts
+++ b/tests/library/web-socket.spec.ts
@@ -148,7 +148,7 @@ it('should emit error', async ({ page, server, browserName, channel }) => {
   if (browserName === 'firefox')
     expect(message).toBe('CLOSE_ABNORMAL');
   else
-    expect(message).toContain(channel.includes('msedge') ? '' : ': 400');
+    expect(message).toContain(channel?.includes('msedge') ? '' : ': 400');
 });
 
 it('should not have stray error events', async ({ page, server }) => {