[thaumasiotes]

> Hence the term (at least in Dutch) that "he is of blue blood" = he rich af.

This is usually said to refer to the fact that someone's skin is so pale you can see the veins through it.

(Also, it refers to pedigree rather than wealth, in English...)

I would expect silver to turn things black, not blue.

(Although see https://en.wikipedia.org/wiki/Argyria )

[goopypoop]

They would hide from the sun to get extra veiny, because they could

[thaumasiotes]

Perhaps, but according to etymonline the term comes from Spain, where certain families described themselves as having "blue blood" to emphasize that they had no Moorish ancestry. The contrast being drawn isn't one between nobles and laborers. It's between indigenous nobles and intrusive nobles.

[_9ptr]

Like the programmers in our time