GB/T 2387-2025 "Reactive Dyes—Determination of Shade and Strength" consolidates three original national standards to establish a unified testing system for reactive dyes. It is applicable for determining the shade and strength of reactive dyes used for cellulose and wool. The standard clarifies the characteristics and applicable processes of five major categories of reactive dyes, specifies testing methods such as exhaustion dyeing, pad dyeing (including the newly added pad-batch method), and printing, and details process parameters such as dyeing temperature, liquor ratio, and time for different dyes. Results can be evaluated visually or instrumentally. The standard also outlines laboratory equipment configuration requirements and key quality control points, providing comprehensive technical support for dye quality control and process optimization, while promoting the standardization and environmental sustainability of industry testing.