Just use the Dark Reader addon instead. Way better and works on almost every website!

Also what's with those permissions!? This is a UI change.

it make the screen dark alright, but the text stays dark too, so you can't read it... This is just dumb.

The reviews and some other elements don't auto-change to white such as the text in reviews, making it unreadable. Tried changing in options and there's no way unless I missed it.