К сожалению не позволяет задать цвет фона неактивной вкладки (я не понимаю с какого дуба рухнули разработчики когда его убрали).

Nova has kinda broken it, there are elements like the border around the "find in page" text box that are bright teal and nothing can fix that in Firefox colour.

I don't really understand the point of this add-on - after installing it and clicking on it, it opens a webpage for creating themes. A URL link would have been enough. Or even better - add it as a developer tool to the menu. Another problem is that you can't start from the currently active theme. You have to start from scratch. That's a shame. Furthermore, it doesn't allow you to edit all the elements and test them in a live preview.

i am sorry, i do not want to discourage the programmer, but i doubt the whole idea... something so simple , like setting colors in a software should be integrated offline in the program itself. while genious makers like decentraleyes make it possible to load needed code from local instead of dozens online sources, we now ping the cloud to set a color ? why should i visit hxxx://color.firefox.url to do this ?
Mozilla! What are you doing, you are about to crush your reputation entirely... i thought you care for security, but now we shout to the web, user x has clicked this button.. and he browses in pink, and his ip is ...... ! yay... well done....

Very good

Very good

Отличная штука

i never asked for this extension to be installed on my browser