Since pre-Hispanic times, bold colors found in nature have influenced crafts and construction projects throughout every area of what is now modern Mexico. Natural pigments including bright greens, yellows, turquoise, burnt oranges and ochre red are still used to this day in the creation of folk art. The creation of these colors an ancient craft itself. For example, red pigments used in Mexican folk crafts have traditionally been made by drying and crushing the cochineal bug; the powder is then mixed into a liquid base and applied to clay, textiles or other surfaces.
The color black is widely used in traditional Mexican folk art, from rock drawings outlined in charcoal to the "barro negro" pottery made from a clay unique to southern Mexico. Black colors for crafts like painting or decorating Day of the Dead skulls have traditionally been made with charcoal pieces, either whole or ground to a fine powder to be mixed with liquid. The famous black pottery from the Oaxaca region in southern Mexico is made with a clay unique to the area. It transforms into a glossy black color through a special firing process which denies oxygen to the clay; the process has remained unchanged for thousands of years.
White also plays its part in Mexican folk art, and since it was chosen as a color of the national flag its importance has only risen. In pottery, some clay turns a creamy white once fired, serving as an excellent canvas for more elaborate decorations. There is even a special clay called "matiz" that is extracted from the earth and ground into a fine powder to create a bright white paint. Sugar skulls and skeletons made for Day of the Dead celebrations are usually left stark white with brightly colored clothes and flowers adorning them.