Brian,
Those plastics are not nylon. they are
polypropylene or
polyethylene. Those materials do not dye well because they aren't hygroscopic. Meaning they dont absorb water. Thats how the dye works. Some plastics will absorbe the dyed water and some wont. It all depends on what the base resin formulation is. Not all "plastic" is created equal.
UH60sSuck,
If you PM me your mailing info and what colors you want I'll be happy to drop a couple in packets in the mail for you. I'm assuming you have a FPO mailing address. More than willing to help out one of our solders. Keep up the good work.

(This is the RCM Solute

)