As I think more about this, I realize that there are illustrations of upper classes as well as lower classes dressed in what i will call "two-toned" armor.

It could well be that the wealthier gentry had fabric covered armor -- we know how these guys loved to show off in fine fabrics -- while the lower classes aped their masters' finery by using paint -- a much cheaper alternative back then (I surmise), and also more readily maintainable than cloth covering, and easier to repair after a battle, too. This would have been more of a concern for a pikeman than for a man-at-arms.

I know there are more but that is the best I could think of right now.