A two-part hair dye composition, including a first part containing an alkali agent, a second part containing hydrogen peroxide, and a non-aerosol type foamer container for discharging a liquid mixture of the first part and the second part as a foam, wherein the liquid mixture contains the following components (A) to (D): (A) 0.1 to 5% by mass of an alkyl sulfate or polyoxyalkylene alkyl sulfate; (B) 0.1 to 10% by mass of an alkyl polyglucoside; (C) 0.01 to 3% by mass of a dimethyldiallyl ammonium chloride-acrylamide copolymer or a dimethyldiallyl ammonium chloride-acrylamide-acrylic acid copolymer; and (D) 0.01 to 0.8% by mass of a higher alcohol.