A driving circuit for driving a light source having an adjustable color temperature is provided. The driving circuit includes a power converter, coupled between a power source and the light source and operable for receiving power from the power source and for providing a regulated power to the light source; and a color temperature controller, coupled to the power converter and operable for receiving a switch monitoring signal indicative of an operation of a power switch coupled between the power source and the power converter, and for adjusting the color temperature of the light source based on the switch monitoring signal.