We did my son's Rossi Trifecta last year, just for kicks (and because he thought it would look cool). We just did it the old fashioned way; bought some decent quality spray paint, gave it a base coat, then started laying vegetation on it and overspraying. Turned out OK. I made him the ghillie suit about the same time.
I have a better picture of the gun with his buck last year, but it's not on this computer.