dying plastic: can it be done?

hi, sorry if the answer to this exists any where on the forum, but i'm meant to be working, and don't have time to look--i read somewhere it's possible to dye plastic, and just wondered what stuff would i use/and where do i get it from. I'm looking to repaint a slight kitbash of energon megatron in to g1 megs colours. I particularly want to try it with the thigh area, since it is a sore spot for paint scraping. Also is it viable to dye a dark plastic with a lighter colour?
Thanks any help would be appreciated, especially on what product, and where best to get it. I still consider myself a beginner.
cheers
Thanks any help would be appreciated, especially on what product, and where best to get it. I still consider myself a beginner.
cheers