Leighton Meester

Wow! Hard to believe that Miss Blair Waldorf used to be a blondie. Though Leighton looks good no matter what, we're glad she got a Gossip Girl makeover! As a brunette, her hair looks shinier and healthier – and it also compliments her face instead of washing it out.

Are you thinking of going darker, too? If you're naturally blonde or have blonde highlights, visit a professional hairstylist: at-home coloring should only be done if you're going one or two shades darker – not ten!

Already a brunette? A handful of brands offer color enhancing, made-for-brunette shampoos and conditioners. Try to steer clear of color-depositing products, though – their hues can be inconsistent.

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