There is a whole whack of information on powder coating cast bullets a bit further down in another forum. Bullet Making.
Basically you bake powdered paint onto your cast bullets in a toaster oven or even your regular oven. It's cheap and easy and some say they don't have to lube the bullets or use the gas checks. I will be playing with that this spring to see if it makes a difference with rifle bullets.
I tried just powder coating cast lead pistol bullets for my 45 LC. No lube or gas check and a lead hardness of 24 Brinnell, as measured by my gauge. The barrel of my 1917 S&W also has very shallow rifling. I'm load at about max for this pistol at the moment but that will change. It's accurate and doesn't foul. I'm impressed.
If you have a powder coating facility close by, go talk to them for a few pointers and ask if they will sell you some of their overspray from their booths. They just sweep it up or collect it in the bottom of a bucket in their dust collector. Makes for some varied colors but so what. If you like solid colors some people insist that BLUE gives the best results. I've used blue, black, red and pink because I was able to pick up small quantities cheaply. I never noticed a bit of difference between them.