This standard specifies a test method for determining the resistance of textile colors to the action of dilute, hot inorganic acids under mild acid felting conditions. The method involves stitching a textile sample together with a standard adjacent fabric, subjecting it to a specific acidic solution to simulate felting treatment, and then assessing its color durability through colorimetric evaluation after rinsing and drying. To conduct the test, laboratories typically require a constant-temperature oven or water bath to maintain stable temperatures, and sometimes a specialized color fastness tester equipped with features such as resin plates and weights to ensure consistent test conditions under specific pressure environments.