1. An image forming apparatus for performing image formation by developing an electrostatic latent image formed on an image bearing member using a recording material, the image forming apparatus comprising: an input unit configured to input a color image to be formed; a specifying unit configured to specify an important color of the input color image; a patch setting unit configured to set a patch on the basis of the important color; a colorimetric measurement unit configured to colorimetrically measure a developed patch obtained by developing an electrostatic latent image of the patch formed on the image bearing member; and a calibration unit configured to perform calibration on the basis of a colorimetric value obtained by the colorimetric measurement unit.