A display device according to an exemplary embodiment of the present invention includes: a display panel including a plurality of pixels respectively displaying a first color, a second color, and a third color; and a signal controller controlling the display panel by processing an input image signal, wherein, in a color weakness mode, at least one color among the first to third colors is displayed with a higher gray than an input gray of the input image signal, and the other colors are displayed with the same gray as the input gray of the input image signal.