yup i still have a couple......the stuff i have is called dylon
take a look at
www.dylon.co.uk
i emailed them when i was playing with it asking them about dyeing plastics and they replied that yes it will dye plastic but they hadnt specifically tested it and couldnt offer any advise on how to do it.
if you look on pbnation there is a big thread in the goggles section (i think) about dyeing plastics that might help you.
generally, boil water, add dye, allow to cool slightly so that the boiling water doesnt melt the plastics.....suspend the item in the dye and leave it till it looks how you want it, keep the temp constant if you can using a cheap thermometer.
once you take the item out rince in stone cold water to close the pores in the plastic. if its not dark enough just put it back in.
dye can also be saved and resused.
good luck!