In the past, primitive people who lived in a cave left various pictures on the wall. A closer examination of these drawings reveals that primitive man used mud to make his drawings. Or, they drew black pictures using charcoal from the tips of the leftover trees. In nature, there are beautifully colored stones and animal shells. For example, shells of shellfish and eggshells. In the olden days, people used to grind them into a fine powder and mix it with oil or kawa (Japanese persimmon juice).
Even today, if you go to a store that sells paints, you will find "iwa-enogu," or rock paints, which are made from natural stones. However, even though we can find colors in nature, not all colors are available, and some colors cannot be found. Moreover, there is a limit to the amount of colors that can be found.
For these reasons, most paints are now made by kneading synthetic dyes with oil. Synthetic dyes are "sources of color" made from petroleum, and are made in factories by combining various chemicals. This is very convenient because all kinds of colors can be produced in large quantities. Now even paints are made from petroleum.