If you want to Hide or Disable the Windows Defender Security Center icon in Windows 11/10 taskbar Notification area, follow these steps.

Go to the website where you want to disable the pop-up blocker. Look for the red X that appears in the address bar when a pop-up is blocked. Click the red X icon.

Red has been dropped again, but Dynamic Color is not implemented in its place. After version 2023.11.26.x, Gmail’s notification icon no longer has a red background.