PLASTI DIP

plasti dip is a spray similar to a can of spray paint, however it isn't paint. instead its a rubberish cementish paintish liquid that goes on and stays on to protect whatever your spraying

the awesome part is that when you want to take it off, it peels right off, in one piece!!!

many people use this (with great success) to temporarily paint their cars, rims, computers, etc

i just used it on my gray plastic reciever for my m4 and it came out great!