Using projection mapping, we can control the appearance of realworld objects by projecting colored light onto them. Since a projector can only add illumination to the scene, limited color gamut can be presented through projection mapping. However, actual color and perceived color are not always the same, and there is often large difference between them. We intentionally generate this difference by inducing visual illusion for extending the controllable color gamut of a projector. In particular, we induce color constancy. We demonstrate changing object color with and without inducing color constancy. Audiences perceive the controlled colors with and without illusion as different color nevertheless these colors are physically completely same.