It's called Armory Coat.
It's very durable, and looks good. It's basically a baked-on paint like duracoat, but developed in-house by SA. I like the Champion, as it is a nice balance for many for CCW. I currently have my Champion slide on my Ultra-compact frame, making it CCO-sized, and love that! I had to buy both to get this, of course, but it was worth it in the end, even if only for interchangeability purposes. The OD green Champions are lightweight, in case you didn't know, and come with Ambi-safety and Novak night sights.
The captive recoil spring design is crap, and should be tossed in the trash when it's time to change recoil springs. EGW will set you up with the correct replacement assembly for very little money, and it will save you a fortune in springs over time.