This standard serves as the foundational principle for a series of standards, with the primary purpose of providing a unified theoretical basis for subsequent color measurement and calculation sections. It is equivalent to the adoption of international standards and specifies the essential professional terminology and fundamental conditions for color measurement, including the use of the CIE (International Commission on Illumination) standard colorimetric system to describe the color coordinates of coatings. Its implementation relies on precision optical instruments that adhere to colorimetric principles, such as spectrophotometers or colorimeters. By measuring the spectral reflectance data of coatings, these instruments can calculate the tristimulus values and chromaticity coordinates under standard lighting and observation conditions, thereby achieving an objective and quantifiable description of color, replacing subjective visual assessments.