Electronic circuitry for color-mixing in an LED light fixture during AC power dimming is disclosed to achieve adjustable color temperature. According to one embodiment, a dimmable LED light fixture has first, second, and third LED light sources, the first and second LED light sources producing white light, the third LED light source producing colored light, the LED driver configured to power the LED light sources by providing a single-channel variable-DC current source having two output terminals, and a current regulator for maintaining the current in the third LED light source path substantially constant as the LED driver output current is decreased when the AC power is reduced by the dimmer module, thereby altering the color of the light produced by the combination of the LED light sources.