well every car on the road today is either, black, blue, red, or white(silver and pearl are alos considered white) so say away from those and you will be at least somewhat unique.
What? How is silver considered white? Pearl, I can understand in a way, because there is an actual pearl white, but silver...
Also, there are more colors on the road than that of what you named. Working at a dealership, I have seen just about every color there is roll off the lot through trade ins. Outside of the very basic narrowed colors you named I have seen yellow, green, purple, pink (yes pink), orange, and even some weird neon 80's custom colors.
Hell, mine doesn't even fit into the colors you named and it is on the road daily, so I guess I don't understand your statement. Mine is a carbon color which in the sun looks like a dark metallic gray.
Op, if you want something custom, why not get with your painter and mix up your own color?