A covering for an architectural opening is provided. The covering may include an outer roller, an inner roller received within the outer roller, a first shade secured to and adapted to be wrapped around the outer roller, and a second shade secured to and adapted to be wrapped around the inner roller. The outer roller may define an elongated slot through which the second shade extends and retracts. Opposite ends of the inner roller may be aligned with corresponding ends of the outer roller. A mounting system may support the inner and outer rollers for rotative movement about a central longitudinal axis of the inner roller. A bottom rail of the second shade may engage the outer roller when the second shade is in the fully retracted position. Rotation of the inner roller when the second shade is in a retracted position may cause rotation of the outer roller.