An illumination system has a plurality of light emitters (R5G5B), a first light-collimator (1) for collimating light emitted by the light emitters, and at least a second light-collimator (2) for collimating light emitted by the light emitters. The first light-collimator is arranged around a longitudinal axis (25) of the illumination system, and second light-collimator is being arranged around the first light-collimator along the longitudinal axis. Light propagation in the first light-collimator on total internal reflection. Light propagation in the second light-collimator is based on total internal reflection or on reflection at an outer surface of the second light-collimator facing away from the longitudinal axis. The cavity (3) is provided between the first and the second light-collimator. The cavity is provided with a switchable element based on electrowetting, wherein the switchable optical element is switchable in a mode of operation reducing the effect of the second light-collimator.