In ancient times, to have ginger hair would mean you were the son of Lucifer (God Bless). Even more embarrassing for the females, their ginger pubic hair would be constantly mocked. Eventually, people became tired of repeating 'ginger pun hair', so the phrase was abbreviated to 'Jubhair'
Guy: "yo! lemme see your pussay!"
Ginger Girl: "k"
Guy: "nah man, das dutty, allow jubhair.."