I agree with Mike. Small differences in application make a big difference. With their white aluminum it is not so sensitive, but with both the polished and just plain aluminum, the thickness of the coat is everything. With either of those two colors I dial the paint flow way back, just slowly misting the paint on. If you put on a very thin, translucent coating it will look pretty smooth and polished. Just a slightly thicker coat looks different.
So I start with a very thin coat over everything. I use Post-it notes for masking, so I can do second and third coats sooner and with less risk than with masking tape. But in any case, I mask off panels, and put down another very thin coat- it will look different. I sometimes then repeat for a third coat on just a couple of thin panels.
I use variation in the base coat for when I want to depict another alloy color tint, say a magnesium area among aluminums.