1. A display device comprising: a display unit that displays an image; a touch detection circuit configured to detect an instruction input provided by a pointing device to a display surface of the display unit, wherein the touch detection circuit includes a drive electrode, a touch detection electrode opposed to at least part of the drive electrode with a dielectric interposed therebetween, and a detection circuit configured to detect the instruction input based on a detection signal generated in the touch detection electrode in accordance with a drive signal applied to the drive electrode; an acquisition circuit configured to acquire information indicating a display color at an instruction input position, the display color being detected by a color sensor included in the pointing device; and a determination circuit configured to perform determination processing to determine the instruction input position based on a color of the image and the color indicated by the information acquired by the acquisition circuit, wherein the determination circuit is configured to collate a color of the image set to be different for each of a plurality of partial regions constituting a display region of the display unit with the color indicated by the information acquired by the acquisition circuit in the determination processing, and wherein the determination circuit is configured to invalidate a detection result that does not correspond to the instruction input position determined through the determination processing among detection results obtained by the detection circuit.