A color adjustable lamp may be controlled using a well-known TRIAC dimmer circuit. The color adjustable lamp comprises two or more light sources. Each light source may output light having a different color. By setting an output intensity of each light source, light having a desired color may be output. A circuit or a processing unit comprised in a lamp driving circuit may detect a set phase angle of the TRIAC dimmer circuit by determining a shape of the supplied alternating voltage. According to the determined shape, the circuit or processing unit controls a lamp driver circuit for each light source in order to control the intensity of the light output by each light source.