In high school I wanted to dye my hair blue, but since I ran varsity cross country and the state regulations clearly stated that hair could not be dyed any color that could not possibly occur naturally (blues, reds, and greens included). To kind of get around the rules, I dyed my hair jet black with blue hues in the sun.
I'm now proud to say that it is back to my dark brown with a few hints of gold (usually when I'm in the sun).