Even if two colors look the same to the human eye, as in the example of the two apples in Part I-11, slight differences may be found when the colors are measured with a colorimeter. In addition, the colorimeter expresses such differences exactly in numerical form. If for some reason the color of a product was wrong and the product was shipped without the problem being noticed, and the customer complained as a result.... The effect would not be limited to only the sales department or the production department, it would hurt the reputation of the entire company. Color control plays a very important role in preventing such problems from occurring.