PURPOSE: To manufacture a colored mirror (dark mirror) having freely selectable base color and excellent decorative effect, by forming a thin transparent reduced lead nitrate film on the surface of a plate glass, and coloring the coating film.

CONSTITUTION: An aqueous solution of lead nitrate is added slowly to an aqueous solution of sodium hydroxide under agitation to obtain a compound liquid. A mixture of 100pts. of a thiourea liquid and about 0.5pt. of the above compound liquid is poured on the surface of a plate glass, and the compound liquid is reduced for about 15min. The glass is washed with boiling pure water, and a mixture of 100pts. of a thiourea liquid and about 250pts. of the above compound liquid is poured on the surface of the glass to effect the reduction of the compound liquid for about 7min. The process is repeated twice to form a transparent film of reduced lead nitrate. If necessary, the film is treated with an adhesive, and colored to a desired color to obtain a dark mirror.