Denim is a tough, cotton twill fabric that is often used in jeans, jackets, overalls, and other sorts of apparel. The term "denim" comes from the French language meaning "dyed cloth," which describes the process of making this fabric. The dye used for denim comes in two main types: natural and synthetic. Natural dyes are derived from plants or minerals and include food-dye colors such as black, blue, brown, gray, green, orange, red, white, and yellow. When applied to textile fibers, these dyes produce colors that vary depending on the type of fiber (for example, black for cotton, brown for hemp), so they are usually combined with other dyes to create different colors. For example, red chile peppers contain three primary colors (red, yellow, and blue) that can be mixed to make many other colors. You can mix natural dyes yourself, but it's not easy - the results depend on how much you overdye your material. For example, mixing just one part blue cornflower to four parts white will give you sky blue, but mixing the same amount of blue cornflower to eight parts black indigo will yield violet.