This question is inspired by What different skin colour can a tiefling officially have?
From the 5e Tiefling player race description, Infernal Bloodline section (PHB, p. 42):
Their skin tones cover the full range of human coloration, but also include various shades of red.
It occurred to me, I don't think we have the full range of human skin colours described anywhere. D&D Beyond says:
humans of the Silver Marches have every possible variation of coloration and features.
But is it every possible variation from real life? If so, does it include blue, for example? Or is it every possible from existing lore?
Fifth edition rules and lore would be preferred, but given that data on this topic seems scarce, older editions or lore not tied to specific edition would be OK, too.
If rules or lore are world-specific, please specify what world is it. I'm mostly interested in most popular worlds, like Forgotten Realms, to keep answers useful for most "regular players".