Generally speaking, according to the samples provided by customers, the colorist uses the company's pigments or color paste to prepare samples as close as possible to the customer's samples, and after confirmation by customers, records the formula of each sample for production reference. There are two color matching methods: 1, manual color matching, skilled use of three-color color matching principle, and the most reasonable formula (economical and reasonable) to allocate the required colors. 2, machine color matching, color matching is a common color matching machine, commonly known as spectral colorimeter, analyzing the proportion of red, yellow and blue through optical reflection; First of all, all the pigments or color pastes of the company should be made into a color database, and then 3-9 formulas can be given through measurement. The colorist subjectively judges the rationality and economy of the formula, makes a sample, tests it again, and repeats it for 2-3 times, which can basically reach a relatively close sample.