Denali rims are on Vaterra and normally they have black rings. I bought my rings from ST Racing - they have few colors available: blue, green, gun metal, orange, red and silver.
Yes, you can paint the wheels white and everything will be okay. I wanted to do the same thing for my other project (white wheels, red or orange rings and stainless hardware), but I decided to keep them black for my Jeep Nukizer.