Hello I hope I don’t post this in the wrong place. I’m new to Manjaro and Linux in general. I would like to know how I can change the color in firefox, for example the color in the bar when I select text, or also the scroll thingy. Changing to say dark theme in firefox doesn’t do anything. This green is absolutely hideous, no offense lol. Enjoying Manjaro very much so far though, finally got rid of Windows (for most parts).
You can customise every aspect of firefox(unlike chrome) as you want. The easiest way to change theme in firefox is to install a theme from mozilla addon marketplace. You can choose any theme you like from there. Some themes even have animations. Customizing or uninstalling themes are also easy.
For KDE go to the System Settings, then Application Style, and click the Configure GNOME/GTK Application Style button at the bottom, and here you can change the global GTK theme for GTK applications, like firefox.
Well, what do u want exactly? You get to change bar, searcg bar, overall color, scroll bar, you get to use animations, then what else do you want? If you don’t like any theme from the marketplace, then use the [the firefox color addon] that @Tomek used to make your own theme.