I'll throw in with the nail polish recommendation-
I've been fortunate enough to find REALLY close matches for my bikes at Target, and Ultra. I also got some Model Master paint from a hobby shop- I've mixed that with the nail polish to get some nice matches.
When I took my bike to the hobby shop- the clerk told me I couldn't have the bike in- when I told him I was trying to match paint he came down and was totally trying to help- That was cool to me.
*yes, I know it's "Ulta" but it's so much more fun to say "Ultra."