Ha - look what popped up:
In medieval Europe, the infamous witch-hunting manual, Malleus Maleficarum, warned that red hair and green eyes were marks of a witch, werewolf or vampire. ... The Spanish Inquisition singled redheads out for persecution, believing their hair to be sure sign that they stole the fires of hell. https://www.interesly.com/red-hair-fear-loathing-medieval-times

Red hair is the rarest natural hair color in humans. (wikipedia) I think of Maureen O'Hara in the film "The Quiet Man" with John Wayne.