Green

Green is one of the colors of light visible to the human eye. Green light has wavelengths in the range of approximately 500 to 565 nanometers, which places it between blue and yellow on the spectrum of visible light.

Most people's eyes contain three types of color-sensing cells called cones. One of these responds strongly to light in the middle wavelengths. Because of how these cone cells respond, humans can distinguish many shades of green, more so than many other colors.

How green appears in nature

Plant leaves and grass appear green because they contain a pigment called chlorophyll. Chlorophyll absorbs red and blue light while mostly reflecting green light. This is why it appears green to people. When chlorophyll breaks down—for example in autumn or when leaves wither—other colors such as yellow, orange, and brown become visible.

Color technology

In light-based systems such as television and computer screens, green is one of three primary colors (red, green, blue—RGB). Combining green and red light produces yellow. In printing systems that work by light absorption (CMYK), green is produced by combining cyan and yellow.

Symbolic and cultural use

Green is used as a symbol of plants, agriculture, and the environment. Organizations and political parties working on environmental issues often adopt green as their symbol, and terms like "green politics" derive from this usage. Another common use is in traffic lights, where green means "go." In Islam and the cultures of many Muslim-majority countries, green is seen as a color associated with prosperity and paradise, as reflected in the flags and symbols of many Arab and African nations.