you can change the Start Menu background color in Windows 11. Instead of showing whiteish or any other default color, you can choose any other color you like. For that, do the following ...
Turn on "Show accent color on Start and taskbar" to use the same color on the taskbar and Start menu. When you go back to the ...
Personally, I prefer the RosePine theme because of its unique look compared to the traditional Windows 11 Start menu. Its neon-like color background is another major plus point of the theme.