Crashes regularly in addition to slowing down the browser.

slows the tabs

I use this for years and I'm very happy with it. Thank you very much!

ColorZilla is back in flying colors , most of the bugs are fixed, many thanks to the developers for listening to the users, 5 stars again, wonderful app

Looks like it just doesn't work with the latest Firefox. Read (and believe) the negative reviews; any remaining positive reviews are clearly for an older version.