A dimmable LED lighting system includes first, second and third types of LED light sources, and an LED driver to control the supply of current on first, second and third channels, respectively to the first, second and third types of LED light sources. The first, second and third types of LED light sources are selected according to their spectral power distribution (SPD) curves. The selected SPD curves together model a dimming color curve that is characteristic of an incandescent light source when the first, second and third types of LED light sources are separately driven with current at predefined power ratios that correspond to dimming levels over a dimming region of the dimming color curve. The dimmable LED lighting system can have a color rendering index Ra greater than 80 over the dimming region.