Tree Style Tab RainbowTabsFork v2.4.21resigned1
This is a fork of https://addons.mozilla.org/de/firefox/addon/tree-style-tab/ with colorful tabs.
This addon displays all your tabs as a tree in a sidebar. Additionally to the original Tree Style Tab Addon this version adds colors to tabs.
Tab colors can be either random, determined by the url for the tab or by a fixed list of colors.
Look at the addon's settings to configure tab colors to your liking.
I'll try my best to keep up to date with the original extensions, but there will always be some lag. Keep in mind that this addon is still experimental and might have some bugs.