I used "PlastiKote Bumper Chrome". I just wrapped tape around the connecter, and gave it a light spray until no amber showed. One bulb had a couple of imperfections due to fingerprints, but you'd have to be looking for 'em to see 'em.
I definitely recommend giving the paint 24-48 hours to dry before installing the bulb. Maybe even heating them a bit to make sure any potential fumes are gone.
Hey Mike, what was the finish (color) on the grill material you bought?
As for amber bulbs, I'll also put these in to comply with IL state law. I read on ClubGP that Silver star also makes amber bulbs now that look silver when off. Have to track down a picture for you guys.