This addon would like to color tabs based on the parent tab that opened the tab.
So say I am at work searching for a solution to a javascript problem on stackoverflow, so I open a bunch of tabs with possible solutions. Then I get distracted, and I start looking for honey badger images on google images, I open a bunch of tabs with honey badger images.
Now all my tabs are mixed up with javascript snippets and honey badgers.

This extension tries to color tabs depending on where they where opened, so that all javascript tabs (tabs opened from the stackoverflow parent tab) are red, and all honey badger tabs (tabs opened from the google images parent tab) are green, so it becomes easy to distinguish them when I go back to look for my js solution.

At the moment this is not possible because of Firefox bug 1320585

So this extension tries to get the favicon of the newly opened tab, and changes the color of the favicon to match that of the parent.

But it will not work

on pages that don't allow content scripts (amo for example)
on pages that dynamically change the favicon
a lot of other cases