I have a black 1991 Trans Am GTA, I need to buy some paint but I cannot find the paint code. It's supposed to be on the RPO code but I do not have it.

A few years ago I got lucky and managed to get a hold of my cars RPO codes thanks to some nice people who worked for GM with registry access. From that list I was able to find this code in relation to the color:

41U : PRIMARY COLOR, EXTERIOR, BLACK

However 41U doesn't really tell me the exact color code (shouldn't it be 4-5 letters long), the color code according to pictures I've seen should be written further down on the sticker and this info I did not get. So can anyone tell me what the color code for a black 1991 GTA should be?