A high-speed electro-optical light gate (40) includes a pair of matched variable optical retarders (54 and 56) positioned between a pair of light polarizing filters (42 and 44) to promote rapid switching between optical transmission states for light rays of the wavelength to which the variable optical retarders are tuned. The projections (62 and 66) of the optic axes of the variable optical retarders are orthogonally aligned so that the response time characteristics of the transitions between optical transmission states of the light gate reflect only the turn-on time response characteristic of the variable optical retarders. A field sequential color display system (78) incorporates a switchable color filter (80) which utilizes the alignment configuration of the variable optical retarders of the light gate to provide light output states of white light and light of three different colors to form an image in full color.