I do beleive black is the correct color for those, or atl leaast the original one's on the '55s were.
Off the topic, I see you're from Indiana. How close to Indianapolis are you? If you're resonably close, there's an indoor swap meet at the State Fairgrounds this Sunday, Harmon's will be there, as well as several other vendors that deal in pre-'72 Chevy and GMC truck parts. Might be worth checking out. I would be there myself, but I got stuck working that weekend,