An apparatus for forming a multi-color image is disclosed which includes a controller that performs an anti reverse-transfer control such that a surface potential of a previously-formed separated-developer-image subset of a plurality of single-color separated-developer-images which has been previously transferred onto an image transferred medium is reduced, prior to a subsequent transfer in which a remainder of the plurality of separated-developer-images is transferred onto the image transferred medium after a previous transfer of the previously-formed separated developer-image subset onto the image transferred medium, to thereby prevent a reverse transfer of a part of a developer material on the image transferred medium from the image transferred medium onto a photoconductor at the subsequent transfer.