This has become a UX phenom. The site used to have a light background. However, I login now to look for older posts I had made for new Windows 11 installs to find a gloomy, dreary and dreadful appearing website. I have no options to revert the colors back.
I will look for this again.
The setting to change the site back to Light Background is under Preferences -> Theme.
Edit: Oops, I was typing when LXP posted. I'm still blurry eyed.
It is still night here. Sorry.
It works. Just be aware that it applies only after being logged in. No way to prevent the login screen from being black.
I've grudgingly learned to live with it.
(I still hate it every time I see a "dark" screenshot).