In described examples of an illumination system, the illumination system includes: at least two illumination modules to output different color light beams to an illumination path; and illumination optics corresponding to each of the at least two illumination modules to receive the light beams and to provide illumination to a programmable spatial light modulator. The programmable spatial light modulator receives the illumination and outputs patterned light to projection optics. The projection optics receive the patterned light and output the patterned light as an output beam through a lens. A controller controls the intensity and duration of light output from the at least two illumination modules and controls the pattern of the spatial light modulator. The output beam is a color formed by combining the different color light beams. The output beam is spectrally tunable.