I've tried ALL the "dark reader" extensions for multiple browsers and though helpful, none ever worked across multiple browsers seamlessly as I'd hoped, until I found the Night Eye extension.
For me, it's a pure winner in every aspect. 95% of sites respond beautifully to the default setting, and if not, I can tweak it and have it remember that site with my tweaks.
For any person who spends multiple hours a day on a computer as I do, get the pro version, it's an eye-saver!