January Jones in Pasadena, California on November 19th, 2012. Credit: FameFlynet

January Jones is embracing her dark side.

The Mad Men actress, 34, debuted a new 'do while out to lunch on Nov. 19, trading her normally shoulder-length blonde tresses for rich, chestnut-colored locks.

Looking effortlessly pulled-together in jeans, a blue sweater, and sunglasses, the single mom wore her newly brunette hair pulled back in a ponytail as she carried son Xander, 14 months, in Pasadena, Calif.

Jones, who welcomed Xander on Sept. 13, 2011, is no stranger to switching things up. Earlier this year, she sported a glossy strawberry-colored style much like the one her redheaded costar Christina Hendricks has.

Tell Us: Do you prefer January Jones as a blonde or a brunette?