Make Start menu design more consistent with other taskbar flyouts

[emvaized]

I'm sorry if I'm stating something obvious, but I haven't found it mentioned in other issues before.

Windows 10 Start menu looks quite consistent on Windows 11 with "Corner preference: Rounded corners, floating menu" option enabled. But there are 2 small differences from other system flyouts (such as Search flyout), which make it stand out:

1. There is no border around start menu, which makes it blend with grey backgrounds. In Windows 11 all flyouts have small darker border to make it stand out more
2. Popup background seems a bit darker and less vibrant than it should be. Please see screenshots below:

System Search flyout:

Windows 10 style menu from EP:

Would be great if these inconvenieces could be resolved to achieve a more "native" look.