The present invention includes a light source having N light generators, a receiver, and an interface circuit. Each light generator emitting light of a different wavelength, the intensity of light generated by the k^th generator is determined by a signal I_k coupled to that light generator. The receiver receives a color coordinate that includes N color components, C_k, for k=1 to N, wherein N is greater than 1. The interface circuit generates the I_k for k=1 to N from the received color components and a plurality of calibration parameters. The calibration parameters depend on manufacturing variations in the light generators. The calibration parameters have values chosen such that a light signal generated by combining the light emitted from each of the light generators is less dependent on the manufacturing variations in the light generators than a light signal generated when I_k is proportional to C_k for k=1 to N.