Time for paint, now what color(s)?

[6 Door King]

Just bought a 1990 C3500 454 with red interior and a few different colors on the exterior. The original color (guessing based on the color around the inside of the back glass) is charcoal gray, sorry I don't know the color name if someone wants to enlighten me. My question is this, what colors if any were combined with this gray/grey in a two tone from the factory? I want to run the second color along the center belt of the truck. Obviously, with the red interior, red has occured to me as a secondary color, but I would like input. Considering silver, black, red, or even a full color change to an alternate setup. The interior is too nice to change, and there is a hell of alot of it on the crewcabs anyways so the outside must change instead.
If anyone wants to throw in pictures of their two-tone/tutone rides I would appreciate the references. Emphasis on gray/red or gray/black combos but others might spark my interest.
Thanks