Accordingly, the applicant of the present application filed for an invention of a color prediction method for predicting the color of the patch to be included in the C×F chart (refer to Japanese Laid-Open Patent Publication No. 2020-159821). A schematic procedure of a color prediction process described in Japanese Laid-Open Patent Publication No. 2020-159821 is as follows. First, from among a plurality of sample colors for which spectral reflectances of a plurality of patches are obtained, a color close to a prediction target color is selected as a similar color. Next, for the similar color, a relational equation is obtained, which represents a relationship between spectral reflectances of a solid patch (a patch with a maximum ink density) and spectral reflectances of a color prediction target patch. Finally, the spectral reflectances of the solid patch for the prediction target color are applied to the relational equation, whereby prediction values of the spectral reflectances of the color prediction target patch for the prediction target color are obtained.