I don't mind Galvatron's tank colours; kinda reminds me of the original Galvatron's toy colours (also used in the G1 comics) *shrug* it's passable as a scifi tank.

I can understand what they're trying to do in terms of giving Galvatron a G1 show-like purple but without allowing that purple to effect the tank mode. As Hero Megatron taught us, tanks don't look so good in purple.