Dye is a substance used to color materials. It is often used to color the fabric used to make clothing. It has low solubility. A pigment won't do this because it won't stick to the fibers of the fabric and color them. A dye can be natural, usually made from plant material such as berries, or artificial, meaning that it is made by humans from chemicals such as petrochemicals.

Most natural dyes are gotten from different parts of a plant like the roots, fruits, bark, leaves, wood, fungi and lichens. Most dyes are synthetic and are made from petrochemicals.