A lighting system having at least three light sources receives an input relating to color coordinates of a target point representing a desired color characteristic for a combined output from the light sources. The system provides color tunable output and/or dimmable output in response to differences in user input. The system also corrects changes in performance of the light sources due to lifetime degradation in each of the light sources. After a period of system operation, outputs of the sources are measured. The system increases the luminosity outputs of each of the light sources by a respective amount relative to the degradations measured in all the light sources; in this manner, the luminosity outputs of the light sources remain substantially constant in relations to each other over the lifetime of the light sources.