Colors are visual perceptions that correspond to categories like red, green, and blue. They derive from the spectrum of light interacting with light receptors in the eye. All languages distinguish a basic set of color categories in a similar order, with black, white, red, green, and blue always included among the first six. The human eye distinguishes colors using three types of color receptor cones in the retina. Color is processed in the brain through opponent channels for red-green, blue-yellow, and black-white. Individual colors have different cultural associations.