just dye it as i said before. if it is a black part you'll need to bleach it to grey first, but then you should be able to dye it. keep in mind you can only dye darker so you cant dye any color white. Lets say you're dying yellow, you may be able to bleach it to off white, and then use white dye to get it very close, but thats about it.
to dye just remove the part, clean it, bleach it, clean it again, than put some dye in a big tub of water, boil it, then stick the part in for 10 minutes.