Add-ons support is over here: https://discourse.mozilla-community.org/c/add-ons

firefoxthemesuploader said

I have tweaked my Lubuntu-theme. For the part of firefox that can be modified with themes my colors do not apply. Thus I created a few themes with plain colors from my Lubuntu-theme and submitted them. All of the themes has benn rejcted, and I do not know why.

This sounds like a GTK 3 OS theme and not either a complete theme for Firefox or image background theme which are hosted at addones.mozilla.org

Yep. Since I did not find a theme that fits my desires I am trying to create one of my own. Unfortunately I found that for different Apps I have to tweak different theme-files for gtk-2, gtk-3 and openbox-3.

And as I do not really know how to set up a theme I simply adapted the themerc, gktrc and css-files of Lubuntu-default theme. This works fine so far but not for the "themeable" part of firefox. As I could not find the appropriate setting to change the standard-grey to my custom blue I decided to create a theme that fits in.

Unfortunately it is apparently no longer possible to simply create a file and set it as theme. Instead you have to create 3 different accounts and have to upload the theme and then hope that it is not rejected.

When I changed to Firefox I did it, because I wanted to be Master of my Browser (Its been about 10 years ago). But it seems to me that "those times they have been a-changing".

I found now the Palemoon fork on https://www.palemoon.org/ which fits my demands. So I thinks it's time to say Good bye to firefox.

Bummer!

Note that Firefox 46.0 and newer requires GTK 3.4 (three.four) or preferably newer and as a result needs GTK3 themes to theme Firefox. GTK2 themes will not work with Fx 46.0 and newer.

The Palemoon is a bit mixture of things now days (not a good thing in long run) including using a new browser engine based on a older Gecko.