Until the last update, the Win 7 used Dark Mode like I wanted however it looks like it was reverted as it has gone back to the white background. The Universal Apps Menu however does use Dark Mode for its menu.
Here's my current version of Windows 11.

I dunno, Would having an option to use system colours or select the colour of choice for the Start Menu instead only black or Colour + White be in the realm of possibility?
I just want consistency between all the Windows UI on my setup.