GB/T 42950-2023 is a leather colour fastness testing standard. It mainly stipulates the test method of leather saliva resistance colour fastness. By simulating the actual scene of leather contact with saliva, the reagents, equipment, operation procedures and rating standards required for the test are clarified. Testing according to this standard can accurately judge the Color Stability of leather under the action of saliva, providing a key basis for evaluating the mass of leather products, especially leather products that are easy to contact with the human mouth, and ensuring consumer safety and experience.