Quick HTML Color Picker
Full user review
"The perfect application..!:O"
It's so small, there's hardly anything to say - which is a BIG plus!
As is the fact, as others have noted, that it doesn't actually install itself and/or tons of drivers etc.
Slightly unnerving initial interface, but that's probably just me...
If you ever want to find an on-screen colour-value, USE THIS!!! I don't know how to use the 'HTML' numbers, but you get the RGB as well, so anyone can figure it out. You could probably even print out the picture/icon, or whatever, and take a note of the numbers, then take (or send) them to a printer's for an exact colour-match, if necessary.
Other than that, I would echo the call for multiple colour recognition lists.