1. A color processing apparatus for determining color patches corresponding to an output device, the apparatus comprising: an input section configured to input colorimetric values of a plurality of color patches of at least one primary color output by the output device; an estimator configured to estimate, based on the colorimetric values of first color patches corresponding to a part of the plurality of color patches, colorimetric values corresponding to second color patches other than the first color patches among the plurality of color patches; a calculator configured to calculate errors between the colorimetric values of the second color patches input by the input section and the colorimetric values corresponding to the second color patches estimated by the estimator; and a determiner configured to determine a plurality of color patches corresponding to the output device based on the errors calculated by the calculator.