to enable FireFox user.css

Posted on Jun 3, 2022

To enable Custom CSS Skinning of the UI:

  • In the URL bar, type about:config and press enter.
  • In the search bar made available, type out toolkit.legacyUserProfileCustomizations.stylesheets .
  • Double click on the false boolean to make it true.
  • Reload ALL instances of FireFox.
  • Enjoy.