Due to the characteristics of aluminum powder with metallic luster and parallel to the coating, in the carrier containing transparent pigment, the glossiness and color depth of aluminum powder change with the change of incident angle and angle of view of incident light, which is called "two-color effect". The aluminum powder is arranged in different layers in the coating film. When the incident light irradiates each layer of aluminum flake, the reflected light is obviously different in brightness due to the different weakening of the coating film through different thickness.