A display device includes: an image display panel including a plurality of pixels each including a first sub-pixel, a second sub-pixel, and a third sub-pixel that display a first color to a third color; and a signal processing unit. The signal processing unit stores an expanded color space, acquires an expansion coefficient for expanding a color displayed by the image display panel to a color that can be extended in the expanded color space, obtains output signals of the first sub-pixel to the third sub-pixel based on at least input signals of the first sub-pixel to the third sub-pixel and the expansion coefficient, and outputs the output signals to the first sub-pixel to the third sub-pixel. The expanded color space is a color space that can extend a color the brightness of which is higher than brightness in a standard color space.