Spraying plastics ?

leave them white, i dont like the idea of spraying plastics, if you do, be sure to use a good plastic primer before the paint! colour is up to you
 
One thing to keep in mind if you do paint them is that every time you scratch them you''ll see a white scratch. So any scratch will stand out more so than if you leave them the way they are. But if you are going to paint them, scuff them up with some scotch brite before using the plastic primer. You'll get much better adhesion.
 
I'm using wetdry 600 sand paper to prep mine hope to have them done in a yellow front and back fenders and black on the hood, tank cover, down the middle to make it look like a WASP.:D