I used to think that paint was a purely aesthetic thing whose only purpose is to make things be pretty colors. Haha, wrong.
Even in a world with no art, paint would still exist, albeit with a significantly shallower palette. For paint provides a corrosion proof covering, provides resistance against ultraviolet radiation, is easily maintained even by completely untrained people, and visually demonstrates the condition of the object in question, because the paint is the first thing damaged.
White paint, colored by titanium oxide, would be the most common shade, and other colors would be discovered on a "when we get around to it" basis. A documentary I saw recently reports that the first colors were literally just ground up rocks, making some colors very expensive indeed (blue and purple only came from expensive gemstones). Chemistry cheapened those colors over time.
Of course, since art exists, there's pressure to develop more and cheaper colors. Artists make all kinds of colored objects, but only make money if they get famous for it. Anything that reduces their costs, they're naturally all in favor of.
So, paint, use it to make stuff pretty, and it'll keep it safe, too. This has been my 12^2th post.