We report a fabrication of a phototunable color filter by combining the Christiansen filter effect and photoisomerization of stilbene. It is known that stilbene isomerizes by irradiation with light, but in that case the light absorption capacity changes only in the ultraviolet region. However, the change in the refractive index due to the isomerization is reflected in the visible light region. A system in which glass beads were dispersed in a solution containing dissolved stilbene as a photochromic dye exhibited a vivid color due to the Christiansen filter effect, in spite of the lack of pigment color. Additionally, we found that the hue of the system can be changed by the isomerization of stilbene upon irradiation with ultraviolet light.