Wouldn't it be nice if you could dress up your first basic horse you buy? It wouldn't be that hard to implement a system where you could apply a horse blanket (made by a tailor perhaps, or sold in the store) to a basic horse and change its "skin". You could dye the blanket too.

I'm tired of having all these basic bay/chestnut horses that I never use once I get the fancier ones. Let's give those poor cold and neglected beasties some blankets!