Redheadedness is often associated with Celtic heritage, but British author Jacky Colliss Harvey says the redhead gene didn't originate from the Celts.
Her book Red explores red hair in the ancient world, through the ages and its portrayal in history, art, literature, religion and culture.
Redheads have long been maligned and been the brunt of jokes and nicknames - gingernuts, carrot top, ging-errs etc, but now there's a groundswell on social media of people with red hair uniting.
Colliss talks to Kathryn Ryan.