The present invention relates to a digital device digital device may comprise: an input unit; a display unit; and a control unit for displaying a color gain adjustment window on the display unit according to a first input, extracting, when a certain color is selected in the color gain adjustment window, unique R, G, and B values of the selected color respectively, increasing or decreasing each of the extracted unique R, G, and B values according to a second input, increasing the gain value of the corresponding color when at least one of the increased unique R, G, and B values is equal to or greater than a first reference value, and decreasing the gain value of the corresponding color when at least one of the decreased unique R, G, and B values is equal to or less than a second reference value.