How does a buck's rack get it's unique color?
Every rack is a unique identifier for a buck. Size, shape and points can all change from deer to deer. Racks differ from year to year, and sometimes differ within the same year. One of the overlooked features of a rack is its color. Some deer can have a pristine white rack while others can be as dark as a good cup of coffee. What causes this variation in color?
Some deer are just going to have darker racks. Just like one buck has the genetics to be a trophy, another will have the genetics for a chocolate rack. Rack genetics are very tricky, too, as 70 percent of a buck's antler genetics actually come from the mom.
As with everything in hunting, location is a key factor as well. Regional differences alter the color of a buck's antlers. In the Midwest, bucks tend to have lighter racks, whereas a deer that's been basking in the Texas sun will probably have a darker rack.
Rubs and Minerals
There are two theories out there that I can refute but I don't buy into much. They are that the minerals a deer eats throughout the year can alter antler color, and the trees that a deer rubs on can darken a rack. While it makes sense that a mineral can stain and alter color, why would they turn black? As you can read in one of my previous articles here, phosphorus and calcium make up 35 percent of an antler. If you've ever seen phosphorus, it's red (it's what you see at the end of a matchstick).
Rubs can affect color, as the blood left in the velvet can stain a rack. The chemicals in the rubbing plant could also potentially stain a rack. I don't like this theory as blood will dissolve rather quickly. That is unless it's in a brand new piece of clothing. As most deer prefer to rub on light and fragrant trees, I don't see that darkening a rack.
I think age is probably the most critical deciding factor to antler color, at least with the deer I hunt. As a buck gets older, its antlers will darken. Also, as it gets older and more dominate, the buck will rub more, resulting in a theoretical darkening of its rack. A deer's rack will bleach out as it is exposed to the elements throughout the year.