A multi-primary color display device (100) includes: a multi-primary color display panel (10) including a pixel that is defined by a plurality of sub pixels including a red sub pixel (R), a green sub pixel (G), a blue sub pixel (B), and a yellow sub pixel (Ye); and a signal converting circuit (20) converting a three-primary color image signal corresponding to three primary colors into a multi-primary color image signal corresponding to four or more primary colors. The signal converting circuit (20), in a case where a three-primary color image signal representing at least an achromatic color of a half tone is input, performs a signal conversion such that variations in luminance levels of the plurality of sub pixels are equalized.