Abstract: The present disclosure provides a touch pen with a color control function, wherein the touch pen is communicatively paired with a user touch display device, wherein the touch pen allows a user input to be written on the display device, wherein the touch pen comprises: an elongate body; a communication unit configured to communicate with the user touch display device; at least one moveable member disposed moveably on the body, wherein the movement of the moveable member on the body controls a color of the user input to be rendered on the display device; and a controller configured to generate a color control signal corresponding to the movement of the moveable member and to send the color control signal via the communication unit to the touch display device.