The process of the invention determines whether toners of cyan (C), magenta (M), and yellow (Y) are all included in toner filled in a toner cartridge 40, based on color information of the toner read from a storage element 50 of the toner cartridge 40 (S100 and S110). When the toners of all these colors are included in the toner cartridge 40, the process sets parameter values for a color image to control parameters (a fixation temperature T, a fixation pressure P, and a preliminary revolving frequency R) of a fixation process (S120). When the toners of all these colors are not included in the toner cartridge 40, on the other hand, the process specifies formation of a monochromatic image and sets parameter values for the monochromatic image to the control parameters (S130). This arrangement effectively ensures adequate formation of a color image and a monochromatic image and desirably prevents excessive deterioration of constituents of an image formation device.