By the way, note this:

How to turn of Dark mode
I tried that
Are you saying that the switch no longer works?
yeah, sort of
If your game window was open before you flipped the switch, then you have to refresh it for the dark mode to change.
I just tried mine and it’s fine on either setting. I suggest you report the problem either by email or in the Help and Support club here:
https://www.chess.com/club/help-and-support
Someone should be able to help.
my thing was fine : https://www.chess.com/settings/themes
I turned dark mode on yesterday and now I can't turn it off. Can someone tell me what to do?