1. An image processing device, comprising: a processing unit that determines color information including one of hue and saturation value of each pixel of a color image; a detecting unit that detects a mode value corresponding to positions of the determined hue values of the pixels; and a changing unit that changes the color information of each pixel by at least changing the determined hue value of each pixel of the color image in accordance with a difference between a boundary value of two predefined hues and the mode value.