The development step uses reducing chemicals, and the exposed silver-halide grains develop to pure silver. The oxidized developer is produced in this reaction, and the oxidized developer reacts with chemicals called couplers in each of the image-forming layers. This reaction causes the coupler to form a color, and this color varies depending on how the silver-halide grains were spectrally sensitized. A different color-forming coupler is used in the red, green, and blue sensitive layers. The latent image in the different layers forms a different colored dye when the film is developed.