A color conversion table corrector corrects a color conversion table used in an image data generation device, and the color conversion table corrector includes a hardware processor that: obtains data related to a print image; obtains first target data based on a first captured image obtained by capturing an image of a first color matching target corresponding to the print image; decides a specific area, in the first captured image, which is not used to correct the color conversion table; and corrects the color conversion table according to the data related to the print image and the first target data based on the first captured image excluding the specific area.