To obtain a diffusion plate with which a bright and beautiful display can be obtd. for a long time by uniformly mixing a colored pearly gloss pigment prepared by coating a mica surface with titanium dioxide and titanium-based multiple oxide so that the incident light transmits as diffused light showing the same colors as the interference colors of the colored pearly gloss pigment.

This diffusion plate contains uniform dispersion of a colored pearly gloss pigment 11 prepared by coating mica 10 with titanium dioxide 12 and titanium-based multiple oxide 15. The incident light 14 transmits as diffused light 16, 18 showing the same colors of the interference colors of the colred pearly gloss pigment 11. The thickness of the whole titanium oxides applied on the surface of mica 10 is controlled to obtain desired interference colors. Namely, the thickness of the whole titanium oxides on the surface of the mica 10 is controlled to about 120 to 135μm to obtain blue interference colors. Or, the thickness of the titanium oxides on the surface of mica 10 is controlled to about 110 to 120μm to obtain violet interference colors.