This data-set is used in research of color difference recognition in unsupervised learning. Each image in this dataset has three colour areas embed inside a QR-Code. Each QR-Code has white area (3x3 cells), black area (3x3 cells) and colour area (3x3 cells). a standard office laserjet has been used to print materials, printing has also been done for standard office A4-paper. The images were captured with an iPhone 7, an iPhone 11 Pro and a Nokia TA-1032, with their built-in camera applications. All of the camera applications used were set to use automatic settings for white balance and other settings. The purpose was to mimic the consumer taking a photo. Package contains folders which have image files. In each folder there are QR-Codes with different colour areas, naming convention of folder is:-Used CMYK intesity + used colours-For example:-- folder "60M" -> 0% C , 60%M, 0%Y, 0%K-- folder "20CY" -> 20% C , 0%M, 20%Y, 0%K