The present invention provides a method of using a rice peroxidase, particularly rice hull peroxidase, having excellent reactivity at high temperatures and reactivity. Dyed substances (dyes, etc.) are decomposed (discolored/bleached) in a washing liquor by means of a rice peroxidase. More particularly, in the case of washing or rinsing a portion with another portion in the dyed fabric with the same washing liquor, the transfer of textile dyes from the dyed fabric to the other fabric is inhibited. Further, textile dyes in a solution or a dispersion solution are bleached. The invention allows excellent prevention of dye transfer in washing or rinsing and thus provides a method better than bleaching textile dyes in a solution or a dispersion solution, and further a composition for prevention of dye transfer and for bleaching.