Photonic crystal, with two or three dimensionally ordered lattices that can control the propagation of light in the manner in which atomic crystals control electrons, has received great attention in recent years. The reflecting optics based on photonic crystal is demonstrated to be promising in such terminal unit of flexible screen as photonic ink, electronic paper and mobile telephone due to its unique optical properties of fadeless color and controllable brightness. Self-assembly of monodisperse nanospheres is a simple and effective approach to creating three-dimensional opaline or inverse opaline photonic crystals (colloidal crystal) in which ordered monodisperse solid or air spheres throughout the network contribute to the optical stop band. When the optical stop band falls into the visible region, a colloidal crystal turns out to be brilliantly colorific.