Answer I'm not going to source but feels right from a US history perspective (which I taught you a decade): whiteness as a concept was defined specifically in relation and distance to the concept of Blackness. You had anglos and teutons and celts and slavs etc etc who didn't see themselves as uniformly white until the use of black slaves tied freedom to whiteness and servitude to Blackness. Why they didn't call it pink instead? Idk