basic primer colors are grey, white, and black. one of my boys got a copperish color for his truck when he molded his tailgate to match his paint better. that's all i know of...i'm not a big paint person though
ive seen all different colors. pink. blue. green. purple. red. they can mix up pretty much anything you want. and you get 2 benefits out of it. better match to the final color, and you can have it whatever color you want until then.