I painted him up the standard way - prime black, foundation red, gold trim, and then a nice coat of Badab Black wash. After that I wanted to do something a bit special on his power fist. I used several layers of red and orange to build up to yellow tips on it. I was pretty happy with the way it turned out.
I have used this guy in a few games. He is 50/50 for me. Either he murders stuff with reckless abandon, or he gets insta killed by a dreadnaught or some loyalist with a powerfist.
Such is the life of a famous Chaos Lord.