ASTM E 2194-2003 "Color measurement of metal flake non-ferrous materials from multiple angles", specifies the standard method for multi-angle Color measurement of metal flake non-ferrous materials. The standard specifies the requirements for measuring instrument performance, calibrating specifications, standardizing the preparation of samples and Measurement angle settings. By measuring reflected light data at different angles, the spatial variation characteristics of materials Color are accurately quantified, providing a unified technical standard and testing basis for scientifically evaluating the Color Appearance mass of such materials and ensuring product conformity.