It cannot even change the background colour for New tab. :-( Come on Firefox devs, not all users know how to use .css, including me. I hate the default white background and i cannot change it. i have been searching for an extension to do this for almost two hours, but none has worked out. Please, devs, develop dark background for new tabs, and remove the white flash.

muy buena

good

Esta bien la aplicacion pero no me aparecia en las extensiones y no podia quitar estilos

The addon steals your browsing history: https://robertheaton.com/2018/07/02/stylish-browser-extension-steals-your-internet-history/