discoloration when i try to shutdown my mac since i updated to Bigsur
Thanks for using Apple Support Communities. We understand that you are seeing some discoloration when you try to shut down your Mac, is that right? Are you seeing the screen flash one solid color or multiple colors? We'd recommend that you try an NVRAM reset to see if that helps. Take a look at the steps here: Reset NVRAM or PRAM on your Mac.
You can also boot your Mac into safe mode, then shut it down, and see if you notice the same issue.
How to use safe mode on your Mac
Hope that helps!