An ophthalmic illumination system includes a light source to emit a light beam and a filter comprising a clear region to transmit visible light in the visible spectrum and a first filtered region to transmit visible light in a first spectral range. The filter is arranged within the optical path of the beam. The system includes a plurality of chromaticity sensors to receive a portion of the light beam transmitted by the filter and output a signal indicating chromaticity of the received beam. The system also includes a processor to receive the signal indicating chromaticity, compare the indicated chromaticity to a target chromaticity stored in memory and, based on the comparison, adjust the chromaticity of the light beam transmitted by the filter by generating a signal to move the filter from a first position in which the light beam is incident upon only the clear region to a second position in which the light beam is partially incident on both the clear region and the first filtered region.