In an image processing device a controller is configured to perform: a first display operation; and a second display operation to display at least one of a target color and a non-target color in a manner different from the at least one of the target color and the non-target color in a printing target image displayed by the first display operation. The target color is a color targeted for color calibration and included in a color calibration space. The color calibration space is defined by a predetermined number of first grid points and a plurality of second grid points. The first grid points define a first polyhedron with a minimum volume enclosing the specified color. The second grid points define a plurality of second polyhedra with the minimum volume together with the first grid points. The color calibration space is a space enclosed by the second grid points.