My old hot rod came with white walls, I was never crazy about them. Tires were originally made from natural rubber which is white, they learned to add carbon to the white rubber in what was known as vulcanization which turned it black and extended the life of the tire. True white walls have the white rubber poured into the mold then the black stuff added on top. The tires on this '51 were made by Coker and are bias ply. They suffered from delamination of the white part, I contacted Coker and they basically said T.S.