The reason for all my replies is because I went through this same process of which color designation i had on my truck
Here is the current listing of colors on the Hummer web site

 

Reviving an OLD thread. I have been searching my brains out for a non-existent paint color. I actually have the window sticker for my 2008 H3A and right at the top it shows: Exterior-Birch White, Interior-Ebony... Well, needless to say, I couldn't find it and was about to beat my head on the desk until I was unconscious and then I finally located the line sheet decal ON the side of the glovebox (NOT on the inside of the 'box' part, but on the flat part to the right and the color is confirmed that it is Olympic White. One of those "Really GM?!?!?" moments.