Rick,
If you have chips for colors you are thinking about using like transport blue, see if your paint supplier can mix a small(1/2 pint)amount for you to put on a part to test. You could also compare a new sample to recently used factory colors and find something new with that color and look at full size vehicles that way. My local DuPont jobber has computer codes for the original colors so I know they are available. I'm going through the same process now to pick a color for my 48 Suburban. Paint chips don't do it for me either. If you don't have the codes for the original colors let me know and I'll send them to you.

55 1st 1/2 ton
48 Suburban


JohnRJoyner
48 Suburban,55 1st 1/2 ton, 53 GMC