No, black and white are social classes not races. What do these titles have in common: black, white, king, serf, peasant,noble.

The only time you would capitalize the first letter of these social caste designations is when it becomes an honorary title attached to a specific name. Queen Elizabeth, King Charles and so on. Common castes don’t get honorific titles. So there is no Serf John or Noble Jack. Common vs honorable or venerable. Calling oneself white or black is just pointing out a class positional rank.