I'm on the Barbarossa scenario from the 1939 campaign and noticed a graphics bug on some of the tiles. When occupied by my units, they become "washed out" and more brown than the surrounding tiles. It only seems to affect tiles with a forest. At first I thought it might have been the after effect of an attack, like a bombing or artillery attack caused it. But, I noticed that it was affecting tiles that I hadn't attacked, ones I just occupied. Plus, ones that were "washed out", weren't later. Here are two photos I have of the "washed out" effect:
