The natural blonde star, who turned 27 on Monday, first experimented with her hue when she dyed it jet black while filming her own reality show -- The Ashlee Simpson Show -- which premiered on MTV in 2004.
From there she changed up her 'do almost once a year. "I love to [dye my hair]. It's something you can always change. You kinda take on a new personality with a hair color," she told PopSugar.
Tell Us: Which is Ashlee Simpson's best hair look?