Mozilla’s Firefox is very changeable thanks to an almost endless selection of themes. A look at the Themes gallery on the official Mozilla website shows what is possible. However, the huge selection also has a huge disadvantage: Because the overview falls by the wayside.
If you are looking for a successful dark theme for the browser, we can recommend the Borderless Dark theme. In direct comparison with Firefox’s standard dark mode, this design appears with darker colors that appear more pleasant. It also looks a lot nicer if you highlight the font in the URL search bar.