1. An image-processing device for performing processing of coloring a skin of an image of a person with a pattern in a certain color, comprising: a color-correction unit that corrects the color of the pattern to determine a color for each region such that the color of the pattern applied to each region varies in a plurality of regions colored with the pattern in the image of the person; and a coloring unit that colors the image of the person with the pattern by superimposing the color for each region on a color of each region of the image of the person, wherein, using a difference in a representative color between any two regions of the plurality of regions in the image of the person, the color-correction unit corrects the color of the pattern to determine the color for each region such that a color difference between any two regions of the plurality of regions is decreased after the coloring.