You can change the Start menu to any custom color you want, but that will, by default, change the Taskbar to the same color.

Microsoft is rolling out a new Start menu for Windows 11 with a unified, scrollable layout that combines all sections into one view and finally adds an option to hide the "Recommended" area. The ...

As we’ve previously covered, Microsoft is working on another redesign of the Start Menu in Windows 11, and one of the new features is that apps will be divided into different categories automatically.