A color filter in accordance with the present invention comprises an activated film layer (2) arranged on a transparent substrate (1), said activated film layer (2) having a color pattern formed thereon by permeating a dye thereinto, and a thin metal film pattern (3) formed on a portion, of said activated film layer (2), which requires the formation of a black mask. Accordingly, the color filter integrated into various display devices such as a liquid crystal display is capable of displaying an image having a high contrast. Further, a method for forming a color filter in accordance with the present invention comprises the steps of forming an activated film layer (2) on a transparent substrate (1); permeating a dye into said activated film layer (2) to form a color pattern; and performing an electroless plating to form said thin metal film pattern (3) which functions as a black mask. Accordingly, the method in accordance with the present invention is capable of easily forming a color filter capable of displaying an image having a high contrast.