Never one to follow fashion convention, Lewis said the secret behind her sapphire locks was her musical alter-ego. "I have a whole other rock 'n' roll life," the singer, who first dyed her hair in June, told People Magazine.
"It's so funny, these two lives that I lead."
While her bright blue up-do took fans by surprise Juliette, is far from the first star to dip into their coloring box and emerge looking like Rainbow Brite!
Check out our gallery of colorful celebs.