^But I'll bet it's painted all one color, not alternating panels of azure, pea green, ghost gray and tan.
Yep... the difference in appearance are caused by the inevitable fact that no two cans of paint are ever QUITE the same color... or that some may have been painted at other times (and so some is sun-faded and weathered more than other might be) and so forth.
In general, the actual paint job of the outside of a carrier, for instance, is going to be two colors... one for "beneath the waterline" and another for "above the waterline." And even that isn't a universal rule. But they'd never... ever... paint it in "plaids."