I've yet to find a lightweight, standalone color picker that can show hex values! I hate having to open geany's color picker everytime I need to find hex values, and so far, everything else I've heard of doesn't seem to do the trick.
Guess this is a sort of late reply/question seeing how this is a month old, but a question popped into my mind when you mentioned you used Geany. What sort of development do you do, if any? I'm interested in getting involved in some free-time application development after my school term is over (which will be in about a week and a half).