How can I paint a kryptonite key? I now have 4 kryptonite keys on my key ring that I carry around for my family.  These are the ones with a black plastic bulb on the key's bow.  In order to make my life easier, I would like to paint it for easy identification.  What type of paint do I need to use along with techniques or other advise.
I used nail varnish, it sticks well to the plastic and is very tough. It's easier to apply than spray paint,  but a bit more fiddly and forms a thicker layer of paint. I also used it to mark the locks. You get bottles in the most absurd colours in a 1-pound shop in the teenage cosmetics section.