A pair of polarizing plates are disposed on two sides of an STN type liquid crystal cell constituted by a liquid crystal twist-aligned at a twist angle of 180.degree. to 270.degree.. A retardation plate is disposed between one of the polarizing plates and the liquid crystal cell in such a manner that the optical axis of the retardation plate crosses the transmission axis of the adjacent polarizing plate at 35.degree. to 55.degree.. The pair of polarizing plates are arranged such that their transmission axes are parallel to each other. The liquid crystal cell is arranged such that the optical axis of the retardation plate crosses the aligning direction of the liquid crystal molecules on the substrate side adjacent to the retardation plate at a predetermined angle. A driving circuit is connected to the liquid crystal cell. This circuit serves to apply a voltage to the liquid crystal in accordance with display data having color information to change the polarized state of elliptically polarized light transmitted through the liquid crystal to change the color of emerging light.