Rated 5 out of 5 stars
Love this add-on and couldn't live without it.
I recently encountered a small bug with ColorZilla and was very pleased to see that the developer was both very responsive and very helpful.
(For those who may experience the same bug :
Description: after using the colorpicker, the cursor remained stuck on crosshair when hovering on various parts of the Firefox UI (mainly the tabs and the main menu).
Solution: in the ColorZilla Options, I changed the statusbar format to something simpler (just %rgb%), restarted Firefox and the bug was gone. I was then able to restore the statusbar format to its previous setting, restarted Firefox again (to be sure) and the bug didn't come back.)