The colour that deer antlers acquire once they are clean of velvet does depend on the type of tree or shrub the buck or stag uses as a fraying stock.
Conifers produce very dark antlers, oak and hazel the more familiar mid-brown, but the process takes time.
These colours are probably sealed in by various waxes and oils from the same source; it would take a great deal of dedication on your part to apply the same process to a trophy in order to colour it!
If you try to inflict the same damage on a tree stem, that even a small roebuck manages, you will understand the incredible strength the animal brings to bear while fraying. There might also be a certain embarrassing merriment if you were seen by passers-by!
Using artificial means you can produce what amounts to a work of art, as many taxidermists do with success, otherwise patient work with teak oil will enhance the antlers, but be warned, it is all too easy to ruin them.