Its as simple as a thing called inventory.
If you have an inventory of 500 pairs of tires, how many do you get in black, yellow, orange and white. Then what do you get stuck with?
Another reason white rims are chosen is because you can better judge an apex of a turn when you can see distance better at hi-speeds.
Every company wants to help customers win races right?
If you want your wheels black, yellow or orange, just have your Ipanema Dealer special order them for you.