'Glee' star Lea Michele stunned on the Emmy Awards red carpet in a blue Oscar de la Renta gown. Even more subtle was her two-tone hair with sunny copper highlights.

"There's a huge hair color trend going around where actresses are letting their hair color grow out a little bit, for dark roots with lighter ends," celebrity hair stylist Mark Townsend told our pals at StyleList from Los Angeles, where he'd just finished prepping both Michele and January Jones for the red carpet. "Jessica Biel, Drew Barrymore and Rachel Bilson are just a few adoptees of the look."

But when actresses are filming a movie or a television series, they are not allowed to change their hair length or color, so their hairstylists have to get creative.

Townsend did just that by lightening Michele's hair for the evening using clip-in hair extensions. "It gave her a very summer feeling," he said. "The Emmys happen at end of summer when everyone is tan and their hair is lighter. Lea's hair is naturally very dark brown, so we went really light with a golden copper hue for the highlights."