An indicating plate for a solar watch, comprising a color diffusion plate which, by virtue of the presence of a coloring agent, a coloring light diffusing agent, a colored translucent substrate, a pattern layer/colored thin film layer and a diffusion layer, is adapted to transmit a portion of light having a wavelength within a range capable of causing a solar cell housed under the indicating plate to generate power. The color diffusion plate is adapted to make it difficult to view the solar cell from the outside through the indicating plate and is also adapted to impart a color tone to the indicating plate.