Looks like the latest and greatest in hair color is obvious. Ombré hair is popping up everywhere during Mercedes Benz Fashion Week! Forget going crazy over grown-out roots– these stars have mastered the gradual fade.

Ashlee Simpson-Wentz was the first to be spotted sporting ombré hair Sept. 10, while sitting front row at the BCBG runway. The long, chocolate locks look healthy and natural. We love her as a brunette! Later that same day, Rachel Bilson was seen between shows at Lincoln Center sporting her cute and curly version of the hairstyle. She chose a bright pink lip color for an overall flirty look.

Kristen Cavallari will never completely abandon her signature Cali-girl blonde, but she couldn’t resist getting in on the two-tone trend at Lincoln Center on Sep. 13. Her new style is way hotter and more mature than her monotone ‘do from The Hills.

Hilary Swank stepped out at the Pamella Roland show Sept. 14 radiating confidence. Hilary always looks red carpet-ready without trying too hard. So glamorous!

I personally love the bouncy look of Rachel Bilson’s hair. What do you think Hollywoodlifers? Who rocks the ombré look and who doesn’t?