It's surprising what the dye is actually going to work on. I have used Rit dye on antler pieces for things like knife handles, etc...and it works quite good. I like to get the antlers and bones to take on an old look. I keep a batch mixed up in my shop and just give it a good shake and it's ready to go again. No heating needed or anything special, just let the project sit in the dye overnight, and then I hit it with a very light polishing wheel.
No idea about the OD colors though. I use a yellow and as it ages, it turns an old looking sort of orange.
