1. A color processing device comprising: a color data acquisition section that acquires color data of a first image output by a first image forming device on a basis of image data; and a first-relationship generation section that generates a first relationship that is a relationship between the image data and the acquired color data, the first relationship being generated by applying the image data and the acquired color data to at least one first relationship candidate prepared in advance in a color gamut wider than a color gamut of the color data and by performing matching on the image data and the acquired color data with the first relationship candidate.