An image processing system is disclosed that is configured to input color image data, generate color image data identification information identifying the color image data, store the color image data identification information in association with the color image data, generate monochrome image data based on the color image data, combine the color image data identification information with the monochrome image data according to a predetermined format and print the combined monochrome image data on a first recording medium. Also, the image processing system is configured to read the combined monochrome image data from the first recording medium, extract the color image data identification information from the combined monochrome image data, read the color image data stored in association with the extracted color image data identification information, and output the read color image data in a predetermined visible format.