The image forming apparatus includes a color conversion processing unit that has an input profile for color conversion to first image data which is image data of a device-independent color space, and an adjustment target profile for color conversion to second image data which represents gradation values of the plurality of color materials, and a simulation profile for color-converting the second image data to third image data of the device-independent color space, a profile adjustment unit that adjusts the adjustment target profile in accordance with the user input, determines whether or not a color difference before and after the adjustment of the adjustment target profile is smaller than a preset threshold value, and updates the adjustment target profile by using the adjustment target profile after the adjustment when the profile adjustment unit determines that the color difference is smaller than the threshold value, and a color difference calculation unit.