Green

Green is a color seen commonly in nature. Many plants are green mostly on behalf of a complex chemical known as chlorophyll. The light of the sun that we see from Earth because of our atmosphere and other various reasons is tinted green.

Green light has a wavelength of roughly 520-570 nm and is one of the additive primary colors, the complement of magenta. Many artists, however, continue to use a traditional color theory in which the complement of green is considered to be red.

People who are red-green color blind can often distinguish between the two colors but confuse them with other colors, e.g., bright green with yellow; dark green with brown.

Uses of the color green

In the Middle Ages, green represented evil or demonic beings (including dragons) and sometimes love. Nowadays, however, ideas associated with this color have shifted.

In heraldry, green is called vert.

Green also symbolizes go because of its use in traffic signals, railway signals and ship signals. It is also the color of information and direction signs. Fire escape exit signs are green in some countries, but red in others.

In night vision goggles, the color green is chosen because the human eye is most sensitive and able to discern the most shades in that color.

In auto racing, a green flag signals the start or resumption of a race.

Because of its camouflage properties, green is typically used for the field uniforms for many military services. It is also used as the dress uniform for many land armies and marines.

Green is a symbol of Ireland, which is often referred to as "the Emerald Isle". The color is particularly identified with the republican and nationalist traditions in modern times, and is used that way on the flag of the Republic of Ireland, in balance with the unionist orange.

Green also serves as a symbol of the Esperanto language. It is said that the color was first suggested by an Irishman, Richard Henry Geoghegan, who apparently suggested it as it was the color of his country, and because it is the color of hope, hope being a strong theme in Esperanto culture. The color is particularly associated with the green star, and is seen too on the Esperanto flag.

"Little green men" refers to the stereotypical portrayal of extraterrestrials with green skin, antennae and a generally human body plan (but with the number of a certain body part often changed).

In the Quran, sura Al-Insan, followers of Allah in Jannah will wear fine green silk.

Green is the color of the snooker ball which has a 3-point value, and also a common color for the baize on a snooker table.

Green is the color generally associated with Plaid Cymru, the Welsh political party - but not for reasons of its political ideology.

Green substances
Food colorings used for green include chlorophyll (E140 and E141), quinoline (E104) and, in countries where it is permitted, "Green S" (E142).

Colloquial expressions

Envy, one of the traditional Seven Deadly Sins, is also called the green-eyed monster (after a phrase in Shakespeare's Othello). A person suffering therefrom is said to be "green with envy". Substances that may impart a greenish hue to one's skin include biliverdin, the green pigment in bile, and ceruloplasmin, a protein that carries copper ions in chelation.
Traditionally, someone who works well with plants is said to have a green thumb, or green fingers.
An inexperienced person is sometimes known as green, probably by analogy to unripe (i.e. unready, immature) fruit. The word greenhorn also refers to an inexperienced person.