In a world that cannot be reached by color, without understanding the real resonance and meaning by color, everyday familiar objects become strange, and we begin to appreciate the contour layout of light and shadow with a new path. Grey is the shadow Shared by black and white. The design characteristic of this case is to reduce the interweaving of color and retain the simple binary logic of black and white. Based on the client's proposed tonal preferences, the water phase design believes that the spatial tonality should be the same as the art world's view of monochrome: less disruption of colours, and more focused on the contours, textures, and stereoscopic shapes of light and shadow.