I dont get why they all have black pubes. Does the artist not know they arent japanese/are natural blondes?
The artist knows their biology better than you. "Carpet matches the drapes" idiom doesn't work 100% IRL, because body hair, head hair and pubes colors are determined by different type of melanins. Blonde hair has a lot more phaeomelanin (which expresses red/yellow color) compared to eumelanin (which controls black/brown color expression), and the reverse is true for those with brown/black hair but pubes ALWAYS has higher concentration of eumelanin compared to phaeomelanin no matter what your hair color is, which (mostly) resulted in darker colors.