A color controller for a luminaire constituted of: a thru-converter operative to convert an input signal to at least one luminaire drive signal; an illumination sampler arranged to sample an output from the luminaire and generate a representation thereof; and a feedback controller arranged to receive the output representation and generate the updatable conversion factor in cooperation with calibration luminance and color values, wherein the thru-converter operation is responsive to a trigger signal for defining a first and a second mode, the first mode for generating the luminaire drive signal for the luminaire responsive to the input signal being a frame luminance signal and target color signals and wherein the conversion to the at least one luminaire drive signal is responsive to an updatable conversion factor, and the second mode for generating the luminaire drive signal for the luminaire responsive to the feedback controller.