That is strange, Madcow, but quite interesting!
Yesterday I found a Galactic Marine in a Wave 3 revision case, and I think he is the 'color variation' everyone was talking about. The variation is not the figure itself, but the backpack! I compared my latest Wave 3 Marine with my Wave 1 Marine and found that Wave 3 Marine has a WAYYYY dirtier backpack than the Wave 1 Marine. Ill provide some pics later today, forgot to do so earlier. Im pretty sure thats the color variation!