To reproduce the natural color of an object through color imaging systems, the range of the reproducible color, i.e., the color gamut, of the color display devices must be expanded, because the color gamut of current display devices such as cathode ray tubes (CRTs) and liquid crystal displays (LCDs) is insufficient. We present a new method to enlarge the color gamut for the LCD device using more than three primaries, i.e., multiprimaries, generated by a diffraction grating and a liquid crystal panel. The optical system for the multiprimary color display is introduced, and its capability of increasing the gamut is discussed. The experimental result displayed by seven primary colors is also demonstrated. © 1999 Society of Photo-Optical Instrumentation Engineers.