I saw a knife once that had an elk antler handle that had all the texture ground off and then it was died green. That was pretty swell, but...
I guess I'm a little surprised at all the different posts on coloring the antler. Here in Washington, if you can actually find a piece with thick enough enamel to use as a handle, the natural colors are beautiful. A very pristine white enamel with dark,dark brown, almost black texture.
I was given plenty of sets of antler that were only good enough to make really pretty file handles. I have bought several pieces from North American Antler in Oregon. You can pick out each piece you want.
The third knife I ever made had a tip from a 6 point/double eyeguard bull (no, I didn't cut the rack, but it was about 5 feet tall before it was cut). I ground it to fit the hand and left the tip as nature left it. It looked like ivory, enough to have 3 full-time makers ask me where I got the ivory....
Just some thoughts.
Nick