A multi-color filter without a so-called bipolar phenomenon for use of color liquid crystal display devices is prepared by such a manner that plural sets of electroconductive circuits are prepared on transparent substrate; a given set of circuits on which a first color layer is to be formed is provided with a feeder circuit traversely in one lot; and the first electrodeposition is conducted by applying a current only to this set of circuits in order to impress a given voltage while voltage is increased gradually to a given level over a certain period of time, thereby forming the first color layer, and the electrodeposition is repeated in the similar way by applying current to each of the remaining sets of circuits.