Optically coherent multilayered film-coated powder having weather resistance and a clear intended color, and processes for designing and producing the same are provided. A substance of the base particles providing an intended function and an intended color are selected; a spectral intensity curve and values in CIELAB color system of the intended color are measured; and with substances capable of being used as the coated layers and refractive indexes thereof being included in factors, substances and thicknesses of the coated layers and an order of formation of the layers are obtained that provide optically coherent multilayered film-coated powder having such values in CIELAB color system that minimizes a color difference and makes a hue ratio proximate to 1, by solving numerical solutions of the recurring formula for film multiple coherence.