You may have dyed your hair every shade imaginable: red, brunette, blond, etc. But have you gone rainbow yet? Celebrities can't stop testing out this hot hair trend, taking on colors like navy (Nicole Richie), green (Katy Perry), and blue (Demi Lovato). Whether you add a sharp shade to your bangs, into your braid, or over your whole head, it's the perfect way to stand out in a crowd. So what are you waiting for? Start scrolling and get some serious Crayola hair inspiration! Then watch our video on this must-try trend.