Credit: David Livingston/Getty; Todd Williamson/WireImage; Alberto E. Rodriguez/WireImage

As the weather cools down, the stars are warming up their hair. Drew Barrymore, Ashley Greene and Scarlett Johnansson have added bright fiery or subtle rosy tones to their locks and now red has become the in-demand color by women everywhere.

"It can make your complexion look brighter and creamier," explains Barrymore's colorist Tracey Cunningham, who first took the star auburn in April.

She shares a few warnings, though: "Darker skin tones can look unnatural with this hue," says the pro, who also advises against hot-oil treatments.

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"Since red pigments don't adhere well to other dyes, heat will make the color fade faster." Still. Cunningham loves the look: "Redheads were once called geeky. But now they're supersexy and beautiful!"