What I use for color is powdered aniline dye; picked some up on the amazing amazon, a small sample pack - you only need a little. Most of the colors mix directly with water, but the blue requires alcohol then water (instructions are included). If I want the color to stand out more, I bleach the briar a bit first.
For wax, I use straight carnuba; I think I got this on amazon as well. To apply the wax, I use buffer wheels connected to a variable speed hand drill - full speed is a little too fast; I use about half speed. I tried using a buffer wheel on my grinder, but that's way too fast - it tends to darken the briar, which you might actually want to do, depending on your goal for color.
There are a few more adept pipe finishers on the forum, including one @JustTroItIn , who may be able to share more expertise on the subject.