 Next are the fast and slow blue-sensitive layers, which, when developed, form the latent image.When the exposed silver-halide crystal is developed, it is coupled with a dye grain of its complementary color.This forms a dye "cloud" (like a drop of water on a paper towel) and is limited in its growth by development-inhibitor-releasing (DIR) couplers, which also serve to refine the sharpness of the processed image by limiting the size of the dye clouds.