From red hair: Information from Answers.com
Red hair (also referred to as auburn, ginger, or titian) is a hair color that varies from a deep red through to bright copper.
Red hair can also be subject to ribbing and ridicule. In the Middle Ages red hair was disparagingly called “judas-colored”, in reference to Judas Iscariot. In modern-day UK and Ireland, the word "ginger" is derogatorily used to describe red headed people. Redheads are also sometimes referred to as "carrot tops." This "gingerphobia"...
A common stereotype of redheads is that they have fiery tempers.