Hi Hauser,
Yes, Diamondback can put white walls on new tires you have shipped directly to them, for $175 per tire + tax & shipping, they "prefer" to sell you one of their tires, they purchase and put white walls on. They will not for liability reasons put white walls on any tires that have been driven on.
At $150 per tire, putting white walls on them would cost more than the tire. Since my car came from the factory with without white walls, the Sprint Classics give the car a more original look.