1. An image forming apparatus comprising: a control unit configured to control a fusing unit to perform both of a first fusing and a second fusing, wherein the first fusing is a fixation in which a first image formed on a medium by using a color material having a metallic color and comprising metal particles is fixed, wherein the second fusing is a fixation in which a second image formed on the medium by using a color material having a color other than the metallic color is fixed, wherein the second image is overlapped with the first image, and wherein the control unit is configured to control fixation conditions so that a larger amount of energy is applied during the first fusing as compared to the second fusing.