Looks awesome!

Near excellent. Quite like having my preferred orange. Only negative I've got is that, depending on the colour chosen, some text is lost -- with orange, the number inside the notification bubble is invisible even though I don't think the text was orange. The tab header has the number though so it's not lost and, if I select all the text, it shows up.

Works Perfectly

This is a great extension, works like a charm! Would love to have the source code be open source though... Very useful, double thumbs up from me!