An image processing system includes: an update unit updating color space information indicating a color space by allowing rotational movement of a selected reference color, taking a line connecting a white color to a black color in the color space as a rotation axis, based on adjustment information indicating that hue of at least one reference color is adjusted, which is in a reference color group including plural reference colors of a RGB system and plural reference colors of a CMY system in the color space; and a correction unit correcting an input image signal based on the color space information.