Before bulk purchasing, validate the color mix forecast checking method on a small number of real vehicles. Sampling can cover colors that sold historically, regional preference, and repaint conditions, and both the sample and the unchecked scope must be written down. Where the supplier cannot explain a whole batch of colors chosen from personal taste alone, ask for a formal correction and review evidence. When setting the check scope, see this vehicle procurement process guide. Lifting the hold on the color mix forecast also needs a written basis.