Hi Dave R.
Do us a favor and fill out a bit more of your profile so we know where you are, there might be a knife maker in your area who can lend a hand. Now I'm a bit hesitant to post my phone number on the internet, but I will be happy to answer specific questions.
If you are after colorization of steel, it's going to depend on the steel composition, what sort of wear characteristics you're after, and a couple other variables. It all really comes down to the material you're working with.
A LOT of what I know came from
http://www.finishing.com/ and reading.