For anyone using the "color picker" extension, there is a better option (Windows only, sorry). I use ClipX, which is a utility for having clipboard history (i.e., you can ctrl+c 10 things and have them all available.) It's amazingly useful, and works exactly as you'd expect out of the box.

It has an extension called Color Picker, which gives you a shortcut for popping up a Color Picker/Eye Dropper tool whenever and wherever you want, anywhere inside you Operating System. It's customizable as to what exactly gets copied to your clipboard. It is a much better option than having an extension, IMO, both because it's part of a utility I use anyway, and because it is available anywhere inside Windows, not just your browser.