It would be very good for protecting vision at night if we had the option to select an all-black theme for Firefox. Hexadecimal color code: #000000 . So all windows and all open web pages (except for text and buttons, the text should be white) should have the color #000000 . I think it is the best color, I have been using it for many years for wallpaper. I don't want to install extensions, I do not like them, they slow down my computer 🙂 and most extensions do not satisfy me. This theme can be integrated into the menu --Add-ons and themes-- (menu that exists in Firefox). (!) Google translate, to be sure 🙂