PURPOSE: To obtain fiber products having washing resistance, showing deep color effects by providing colored fiber product with methylhydrogen polysiloxane resin, treating with low-temperature plasma and then topping with a resin having washing durability.

CONSTITUTION: Colored fiber product comprising natural, regenerated or synthetic fibers is provided with a processing agent consisting essentially of methylhydrogen polysiloxane resin and treated with low-temperature plasma and topped with a resin (e.g., silicone elastomer resin or polyurethane resin) for resin processing having washing durability to give fiber products having excellent deep color effects and commercial value.