Popcorn is made up of three main components: endosperm, germ and the pericarp (also known as hull or bran). The endosperm is made up of soft and hard starch granules. The endosperm is always white or yellow in color and is a carbohydrate. The function of the starch is to provide energy for the living part of the kernel, more commonly known as the "germ" or "embryo." The outer hull of the kernel is the pericarp, which is made of cellulose. The pericarp or hull is usually white or yellow in color, though the range of colors includes red, black and many colors in between.