A color filter of a liquid crystal on silicon (LCOS) display device is disclosed, including a substrate including a plurality of pixel regions wherein each pixel region includes a first color dot, a second color dot and a third color dot; and a first color resist, a second color resist and a third color resist disposed in the first color dot, the second color dot and the third color dot on the substrate, wherein each of the first color resist, the second color resist and the third color resist includes at least one opening.