dab a drop of acetone on the plastic in question. if it melts a spot before it evaporates, you probably have a piece of ABS and SHOULD NOT heat it to dyeing temperatures, because those are also softening/melting temperatures. it can be done if you are very very very careful but you will need to ruin several pieces in experiments with your own individual gear before you know the exact threshold temperature.
why bother?
if the plastic survives the acetone test, it is PBT and can be dyed with RIT with excellent results, depending on the color.
in another thread, I requested comments on good/bad colors. for me, scarlet, sunshine orange, black, and bright yellow worked great, while dark green and cocoa brown did not.
I have had good luck painting cases with "Dupli-color" $8 per can at NAPA, good for about 3 cases, but I would not trust it on the keys themselves.
