Paintball paint is pretty permanent.... the only thing I can suggest is use Oxy Clean. Mix the thick solution & soak it into the stain for a while, then wash it. It's safe on colors so you don't have to worry about a big bleach stain. Good luck!
...something else... please read!? My bf had a warrant for an unpaid traffic fine of $750. he lost his job and fell behind on paying it and they put a warrant out. Well he was pulled over on 4th of July, and the cop asked his name (he was a passenger in the car) and he said his last name was...