Just thought I'd pass this along. My brother who restores vintage motocross bikes, needed nylon lock nuts that were red to finish off the would bee factory look. The bike originally had red nylon lock nuts. He was reading some stuff on a restoration forum that would probably work. He took a couple packs of cherry Kool-Aid, add those to a half a pint of water mixed until all crystals were dissolved. Dropped in the white nylon lock nuts and let them sit for about 42 to 72 hours. It works like a charm.
I'm not saying that you would like a red gun but you get my drift, there are other colors.
