Provided is a method for hair dyeing or bleaching using a two-part hair dye or bleach kit including a two-part hair dye or bleach composition including a first agent (1) which contains an alkaline agent and a second agent (2) which contains hydrogen peroxide, a container body (12a), and a pump foamer (20) attached to the container body (12a). At least one of the first agent and the second agent contains a foaming agent. A viscosity of liquid mixture (3) is in a range of from 1 to 300 mPa·s at 25°C. A discharge mass of the pump foamer (20) per single depression operation is 1 g or more.
