A switchable color filter (11) includes three polarizing filters (12, 14 and 16) and two zero to substantially half-wave optical retarders (36 and 38) and is incorporated in a field sequential display system (10) to provide output states of light of three different colors to form an image in full color. Each one of four preferred embodiments (11,11 a, 11 b, and 11 c) of the switchable color filter provides the output states of three colors. The third and fourth preferred embodiments (11 and 11c) provide a fourth additional output state of, respectively, white light and light of a color which is a combination of two of the other output state colors. The optical retarders comprise nematic liquid crystal cells (100) having fast relaxation times to operate the display system at video rates.