Many thanks dude, I thought they would have depended on what spur you were running.
My MI1 is a drift/bashing car for I'd be better with a gray belt? It only has a 21x2 drift motor in it.
My MI3 has a Orion Vortex 3.5 brushless in it, so I'd be better with a black one for it?
I'm in no rish as I've fried my ESC in the Mi3 and i'm struggling to get another within my budget, paydays 16 days away