Abstract: An illumination system in accordance with an embodiment hereof includes a plurality of LED units, a system controller, at least one sensing unit, and a plurality of local controllers each associated with at least one LED unit. Each LED unit includes a plurality of differently colored, independently controllable LEDs forming a color gamut. The system controller generates control signals for each of the LED units consistent with a desired system-level output. The sensing unit(s) senses an operating state of the LEDs during operation thereof, and each local controller includes a memory and a compensator. The memory includes calibration data for use over a short time period, and the compensator updates the calibration data based on measurements from a sensing unit over a long time period. Based at least in part on the calibration data, the local controller operates the LEDs of the LED unit to maintain output intensities consistent with commands issued by the system controller.