A color identifying device includes a mount block, a color detector, a lens and a color identifier. A reactive board having a plurality of surfaces to be measured in respective predetermined positions is mounted in the mount block. The color detector has a plurality of color measuring areas corresponding respectively to the reaction surfaces of the reactive board mounted in the mount block. The lens forms images of the surfaces of the reactive board mounted in the mount block on the respective color measuring areas. The color identifier identifies the colors of the surfaces based on output signals from the corresponding color measuring areas.