That could be the case, too. Artistically and Phsycicsally, something that is larger or closer will look like a different shade or sometimes a different color because it reflects more light (or for the ones that are closer, the light they reflect has less stuff to screw up the view than they would at farther away). Ever notice how all the orbital pictures of Mars looked kinda orangish reddish, but the pathfinder photos were a lot, lot brighter? That's why. Though, yes, the atmosphere probably had something to do with that.