Free: Contests & Raffles.
Most has to do with what they rub them on.
I think it has more to do with genetics..I've seen bucks in the same area with light and dark antlers. Also in velvet, the antlers are either light or dark in the same area.Rubbing on alder or willow might make them redder or blacker at the bases though.
I've killed a critter or 2 in the velvet and they are bone white underneath except for the dried blood. Its what they rub on.
Every year at camp we see a scrape at one of the sign posts. Wonder what rubbin that post does for the color.