An extrusion die device for a molding machine includes an accumulator which includes a housing, a core extending into the housing, and a main passage formed between the core and the housing and having interconnected upper and lower passage sections. The upper passage section has inner and outer annular passages spaced apart radially from each other. A die head has a die orifice and a die exit connected to a bottom end of the lower passage section. An extruding unit includes an annular plunger disposed movably within the housing, and dividing the upper passage section into the inner and outer passage sections. Two differently colored plastics can be extruded by the single annular plunger from the inner and outer passage sections through the die head.