In the preceding pages, we have talked about how color appears and how to express color. In the next section, we will discuss the basics of color, such as what makes an apple red and why the same color may appear different under different conditions. Most people take such things for granted, but it's surprising how little people actually know about them. For color control in the production area or in scientific laboratories, as greater strictness is demanded it becomes necessary to know more about the nature of color. Let's delve deeper into the world of color.