For Hexum

[Vyper]

I think you'll like this even if you are considering a career change.

http://www.unimelb.edu.au/webcentre/tools/developertools/pantone.html

[BuddhaMan]

Not quite the same thing and a little outdated, but still handy for web developers:

http://www.visibone.com/colorlab/big.html