Open up about:config and go to layout.css.prefers-color-scheme.content-override and set it to one of the following:

0 => Force a Dark background

1 => Force a Light background

2 => Follow the System theme (default in Firefox 94)

3 => Follow the Browser toolbar theme (default in Firefox 95+)

    • Possibly linuxOPEnglish
      21·
      8 hours ago

      Readability

      The Firefox light UI sucks but I don’t want website turning into black unreadable nonsense.