A psychophysical experiment is carried out to evaluate the color difference between pairs of color digital images and their modulated versions, which are displayed on a professional liquid crystal display (LCD) monitor, using the category judgment method. The modulated images for six original images are generated with variations in five attributes, namely, lightness, chroma, hue, resolution, and sharpness, considering both their chromatic and spatial characteristics. Several color difference evaluation methods, namely, CIELAB, CIEDE2 000, CAM02-UCS, S-CIELAB, and iCAM, are compared based on the experimental data. The results demonstrate that the performance of iCAM is the best for predicting image color difference.