> My impression is that they were often linked to caste or class, where higher-class people spent more time indoors while lower-class workers spent more time out in the sun.
I'm no expert on the topic, but i heard people refer to this sort of social symbol and discrimination as "colorism".
For anecdote, in France, "sang bleu" (blue blood) used to refer to the nobles and higher classes, as they didn't work the fields, and their thin and pale skin let see through the blue-looking veins. From what i hear, it appears before the revolution this biological distinction was formally racialized: the higher classes with their never-sighted "blue blood" was another "race" as the lower peoples whose spilled blood we could confirm was red.
I'm no expert on the topic, but i heard people refer to this sort of social symbol and discrimination as "colorism".
For anecdote, in France, "sang bleu" (blue blood) used to refer to the nobles and higher classes, as they didn't work the fields, and their thin and pale skin let see through the blue-looking veins. From what i hear, it appears before the revolution this biological distinction was formally racialized: the higher classes with their never-sighted "blue blood" was another "race" as the lower peoples whose spilled blood we could confirm was red.