An Irish person, since every single Irish person has fluorescent orange hair. They were used in train tunnels in England for luminescence before modern paint was created.
"Why’s that scruffy alcoholic have blinding orange hair?"
"Oh, he’s just an Irishman – a carrothead, if you will."
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi