>>7199516Would you be willing to be a guinea pig? People have used Rit dye in the past to dye plastics, but you had to boil the part in water for the dye to take effect, but that was for plastics used for the bodies for figures like ML and DCU, I don't know what your helmet is made from. There also paint for doing those cheap stained glass craft project you see at places like Walmart.
