Green

Green is the color between cyan and yellow on the visible spectrum. It appears when light with a dominant wavelength of roughly 495–570 nm reaches our eyes. In art and printing, green is made by mixing yellow and cyan, while on screens it shines as one of the three main colors—along with red and blue—that blend to make all other colors.

Nature gives us the most green thanks to chlorophyll, the chemical that helps plants photosynthesize and turn sunlight into energy. Many animals also turn green to blend into their leafy homes as camouflage. Some green stones, like the sparkling emerald, get their color from minerals such as chromium.

Across history and around the world, green carries many meanings. In Europe, it was the color of wealthy merchants and common folk, unlike the red reserved for nobles. It is linked with Ireland, Gaelic culture, and in many faiths it stands for the beauty of Paradise. Today, green most often reminds us of nature, life, health, and hope, making it the color of the environmental movement and groups working for a greener world. A green light tells us it’s safe to go, and a green card marks permission to stay in a new home.

Etymology and linguistic definitions

The word green comes from old words in Middle English and Old English, related to words for grass and grow. It shares roots with words in German and other old languages, coming from an ancient word meaning "to grow". The first known use of green to name a color was around the year 700.

Latin also had a word for green, viridis, which led to words in many languages, like the French vert. Other language groups, such as Slavic languages and Ancient Greek, also developed their own words for green, often linking it to fresh plants and new growth.

In some languages, like old Chinese, Thai, old Japanese, and Vietnamese, the same word can mean either blue or green. For example, the Chinese word qīng covers both colors. Modern Japanese has a specific word for green, midori, but in some cases, it still uses the word for blue, ao, to describe green things like traffic lights or green leaves. Vietnamese uses xanh for both blue and green.

Modern European languages see green as a color around 520–570 nm, but many other languages group blue and green together or have different ranges for what they call green. Green only appears as its own color category in languages that have a full set of six color names: white, black, red, green, yellow, and blue. In some languages, new words for green have been created recently from other meanings.

In science

Color vision and colorimetry

In science, green is the color we see when light has a wavelength of about 495 to 570 nanometers. Our eyes are most sensitive to green light around 555 nanometers, which looks yellow-green. Green appears when certain cells in our eyes are triggered more by green light than by red or blue light.

Green is one of the main colors used in screens and paintings. In screens, green is made by mixing red and blue light. In paintings, green can be made by mixing yellow and blue paints.

Lasers

Green lasers are very popular because they are bright and affordable. These lasers work by using special crystals to create green light. Green lasers are used for many things, like pointing, showing light shows, and even helping control birds.

Pigments, food coloring and fireworks

Many green colors come from minerals. For example, emeralds are green because of tiny amounts of chromium or vanadium. Artists have used green pigments for centuries, like verdigris made from copper, though it was not always safe.

Food does not naturally have green coloring approved for eating, but chlorophyll from plants is sometimes used. Fireworks make green sparks using special chemicals like barium salts.

Biology

Many plants look green because of a chemical called chlorophyll, which helps them make food from sunlight. Animals often look green to blend in with plants. For example, some spiders and frogs are green to hide better in green places.

Green eyes

People do not actually have green pigment in their eyes. The green color comes from a mix of brown pigment and the way light scatters in the eye. Green eyes are most common in Northern and Central Europe.

In history and art

Prehistoric history

Cave paintings from ancient times don’t show green colors, but people in northern Europe made a green dye from birch tree leaves. This dye wasn’t very good—it looked more brown than green. Ceramics from ancient Mesopotamia show people wearing bright green clothes, but we don’t know how they made that color.

Ancient history

In ancient Egypt, green meant new life and growth. It was linked to the yearly flooding of the Nile River, which made crops grow. Egyptian artists used a mineral called malachite to make green paint for tombs and pictures. They also mixed other colors to get green. Green was a happy color for Egyptians—it stood for health, new life, and even the sea.

The Romans liked green too. It was the color of Venus, the goddess of gardens. They made special green paints and used them in art and buildings.

Postclassical history

During the Middle Ages and the Renaissance, the color green showed a person’s job or rank. Merchants and regular people wore green, while nobles wore red. Artists began using green in their paintings to show wealth and status. Some famous paintings, like the Mona Lisa, have green clothes to show the person was important.

Modern history

In the 18th and 19th century

In the 1800s, new green paints were made that were brighter and stronger than old ones. Artists like John Constable and Jean-Baptiste-Camille Corot used green to show the beauty of nature. Green also became linked to feelings and moods in art. Artists like Vincent van Gogh used red and green together to show strong emotions.

In the 20th and 21st century

In the 1980s, green became a symbol for the environment and new political ideas in many countries. It stood for taking care of the Earth and for new ways of thinking that were different from older styles.

Symbolism and associations

Safety and permission

Green can mean that it is safe to go, like when you see a green light at a traffic signal. Long ago, green and red were used for railroad signals. The very first traffic light with green and red lamps was put up in London in 1868 but it broke the next year. In 1912, the first modern electric traffic lights were installed in Salt Lake City, Utah. Red was picked because it stands out and means danger, while green was chosen because it looks different from red. Today, a green light shows that a system is on and working well. In video games, green often shows health or that a goal has been finished.

Nature, vivacity, and life

Green is the color most linked with nature, energy, and life in Europe and the United States. It is the color of many groups that care for the environment, like Greenpeace, and of Green Parties in Europe. Cities often use green for parks and gardens, and they may put green bins out for trash. In Europe, a green cross is used to show where pharmacies are.

In China, green is linked with the east, sunrise, and growth. In Thailand, green is lucky for people born on Wednesdays (light green if born at night).

Springtime, freshness, and hope

Green is the color most linked with spring, new beginnings, and hope in the United States and Europe. Green is often used to show rebirth, renewal, and eternal life. In Ancient Egypt, the god Osiris, who ruled the underworld, was shown with green skin. Green as a color of hope is tied to the idea that things will get better after hard times, like flowers blooming after winter.

Youth and inexperience

In Europe and the United States, green is often linked with youth. It is used to describe someone who is young or not very experienced, like how we talk about green cheese (a fresh, young cheese) or a greenhorn (someone who is new and not experienced).

Food and diet

Green is used more and more by food companies and governments to show foods that are vegan or vegetarian. In India, vegetarian food must be marked with a green circle. In 2021, India started using a green V to show vegan food. In Europe and the United States, a green V made by the European Vegetarian Union is used to label vegan and vegetarian foods.

Calm, tolerance, and the agreeable

Studies show that green is the color most linked with calm, agreeableness, and tolerance. Red is linked with heat, blue with cold, and green with a comfortable temperature. Red is linked with being active, blue with being calm, and green is in the middle — a color of balance and calm. Blue and green together show harmony. Tests show that green can lower negative feelings and boost creativity.

Jealousy and envy

Green is often linked with jealousy and envy. The phrase “green-eyed monster” was first used by William Shakespeare in Othello: “it is the green-eyed monster which doth mock the meat it feeds on.” Shakespeare also used it in The Merchant of Venice.

Dragons, fairies, monsters, and devils

In stories, tales, and movies, fairies, dragons, monsters, and devils are often shown as green.

In the Middle Ages, devils were sometimes shown as red, black, or green. Dragons were usually green because they were like reptiles with heads, claws, and tails.

Chinese dragons are often green, but unlike European dragons, they are kind. Chinese dragons stand for strong and good powers, especially control over water, rain, and big storms. The dragon is also a sign of strength and good luck. The Emperor of China used the dragon to show his power. The dragon dance is a popular part of Chinese festivals.

In Irish and English stories, the color was sometimes linked with magic, and with fairies and spirits. The Irish fairy called a leprechaun is often shown wearing a green suit, though before the 1900s he was usually described as wearing red.

In theater and film, green was often linked with monsters and things that are not human. The earliest Frankenstein films were in black and white, but in the poster for the 1935 version The Bride of Frankenstein, the monster had a green face. Actor Bela Lugosi wore green-colored makeup for the role of Dracula in the 1927–1928 Broadway play.

Poison and sickness

Green can also mean the opposite of good health — it is often linked with poison and sickness. Long ago, some paints and colors that looked green were very poisonous because they had metals like copper in them. A drink called absinthe was known as “the green fairy.”

A green color on someone’s skin can mean they feel sick. The phrase “green around the gills” means looking sick. In some Far East cultures, green is used to show sickness or feeling unwell.

Social status, prosperity and the dollar

Green in Europe and the United States is sometimes linked with wealth and success. From the Middle Ages to the 1800s, it was often worn by rich bankers, merchants, and landowners who were not nobility. The benches in the House of Commons of the United Kingdom, where wealthy landowners sat, are green.

In the United States, green is linked with money because since 1861 the back of the one-dollar bill has been green. Green was chosen because it helped prevent people from copying the money, and because it did not show through the thin paper and mix up the pictures on the front. Green is still used today because people now link it with a strong and stable currency.

One famous use of this idea is in The Wonderful Wizard of Oz. The Emerald City in the story is a place where everyone wears glasses that make everything look green. Some think the author, L. Frank Baum, used the city’s color to show the money system in America at the time, when people were talking about using paper money instead of gold.

On flags

See also: Green flag

The flag of Italy was inspired by the flag of France. The green color came from the uniforms of the army of Milan.

The flag of Brazil uses green, which came from the flag of the Empire of Brazil and represents the House of Braganza.

The flag of Lithuania features green to show the beauty of nature, freedom, and hope.

The flag of Ireland includes green to represent the culture and traditions of Gaelic Ireland.

The Flag of Saudi Arabia has green as the color of Islam.

The flag of India uses green to represent hope or prosperity.

The flag of Pakistan has green to show that most people follow Islam.

The flag of Bangladesh has green to stand for the lushness of the land.

The flag of Nigeria uses green to represent the forests and natural wealth.

The flag of Jamaica includes green for the lush vegetation and hope.

The flag of South Africa includes green as one of the colors of the African National Congress.

In politics

See also: Green politics

The color green has been important in politics for many years. Long ago, in the 17th century, the green harp flag was a symbol for people in Ireland who wanted their country to be free. In the 1970s, green became a color for political groups in Switzerland that focused on protecting the country and its traditions.

In the 1980s, many new political parties across Europe started using green to show their concern for the environment. They chose green because it is the color of nature and growth. One of the biggest green parties is in Germany, where it started in the 1980s.

Greenpeace is an environmental group that began in the 1970s. They work to protect the planet and have branches in many countries around the world.

Green is also used by political groups in Australia, Puerto Rico, Indonesia, and Taiwan to show their ideas and goals.

In religion

Green holds special meaning in many religions and traditions. In Islam, green is a sacred color. It is said that important religious figures wore green, and paradise is described as a place where people wear green silk robes. Green is also important in Christianity. Priests and ministers often wear green clothes during church services at certain times of the year. In some Christian traditions, green is used to celebrate important holidays like Pentecost and Christmas.

In other traditions such as Paganism, green symbolizes growth, balance, and good fortune. It is often connected to nature and renewal.

In gambling and sports

Gambling tables in casinos are often green. This tradition began in Venice in the 16th century. Billiards tables are also covered with green cloth, a practice that started in the 15th century when the tables were colored like the grass used for outdoor games.

Green is a popular color for sports teams. For example, the Green Bay Packers, an American football team, wear green uniforms. The Boston Celtics, a basketball team, is known for its green and white colors. In karate, taekwondo, and judo, a green belt shows a person's skill level in the sport.

Idioms and expressions

Here are some fun phrases that use the word "green":

• Having a green thumb (in American English) or green fingers (in British English) means you love gardening and are really good at it. This phrase became popular in 1925 from a BBC gardening show.
• Greenhorn is a word for someone who is new and doesn’t have much experience yet.
• Green-eyed monster is another way to talk about feeling jealous.
• Greenmail is a finance term from the 1980s on Wall Street. It means when a company buys back its own shares at a high price to avoid being taken over by another company.
• Green room is a resting place for actors in a theater or guests waiting to appear on TV. The name comes from a green-colored room at the Theatre Royal, Drury Lane in London from the late 1600s.
• Greenwashing is when a company talks a lot about being good to the environment, but it might not actually be doing much to help.
• Green around the gills describes someone who looks sick.
• Going green means trying to help take care of our planet, like by recycling things we use.
• Looking green is a way to say someone looks very unhappy or disgusted.