A color image forming apparatus 1 includes: a multiple number of process printing units 20, each having an photoreceptor drum 21 for bearing a developer image formed with a toner corresponding to a different color of color-separated image information; a transfer belt 31 to which a multiple number of developer images are comprised in layers; and a transfer roller 36 for transferring the developer images that have been comprised in layers on transfer belt 31, all at once, to recording paper, wherein the multiple number of process printing units 20 are arranged along transfer belt 31, and is characterized in that among the developer images to be transferred from the photoreceptor drums 21 of multiple image forming units 20 onto transfer belt 31, the toner for the developer image of the color to be transferred first is specified to produce a base-layer of the color images of information.