I knew a Mexican guy in LA, his mom was a redhead from Mexico City... I’d have NO way of knowing (lol), but it looked natural enough
the Irish emmigrated to Mexico at the height of the Civil War.
There were 3 choices presented to any man in the warring states:
Put on a uniform.
Pay $300 to exempt oneself
Run like hell to another sovereign state
I have a friend in El Paso whose family is from Juarez and she is a red-head with a 'tan' (the way she puts it). She looks Scot but all her family is from Mexico going back several generations.