Rich
Many companies sell prepainted helmets, but they are usually done up to resemble F1 driver's helmets. Otherwise most helmets come in glossy white.
Make sure you don't buy a motorcycle rated helmet. You will flunk your tech inspection if that's the case.
I've used an excellent helmet painter who is based in Texas, Jack Bich. Here's his website which will give you some ideas for a paint job.
www.helmetpainting.com Think about going with something snappier than just a plain color, that's what we do in vintage racing since that's how helmets were painted back in the day. Graphics are now so easy for an artist to do that it's a lot more fun to style your helmet.
Do yourself and your family a favor and buy a good Kevlar full face helmet. This is the time to make an investment in yourself. I've always favored Bell helmets. Many guys I've raced with are fond of the Bell M3, they run $500-600.
http://www.bellracing.com/