The rainbow has seven colors: red; orange; yellow; green; blue; indigo, and violet. However, there is a whole range of colors that we cannot distinguish with the naked eye. A rainbow is not a pure spectrum. It’s made of many spectral colors that overlap and mix.
What are rainbows?
Aristotle is known as the first scholar to spend a lot of time studying rainbows and what they are. Many scholars and scientists throughout history have continued these studies; rainbows are created when light (usually from the sun) passes through water droplets in Earth’s atmosphere.
What are rainbows commonly associated with?
- In the Book of Genesis of the Hebrew Bible and the Christian Old Testament, a rainbow comes after the flood in the story of Noah as a symbol of God’s promise to never destroy all life on Earth with a global flood again.
- In later Irish folklore, it is said that leprechauns hide pots of gold at the end of rainbows.
- For LGBT+ people, the rainbow is a symbol of diversity and pride. It can often be seen flying on flags as a part of Pride events. In addition, many LGBT+ people and their allies wear rainbow clothing or own rainbow accessories all year round.
What is a color?
Color is what your eyes see when light is reflected off an object. To see color, you have to have light. Color has three properties:
- Hue: This is the name of a color, like red or blue.
- Value: This is the lightness or darkness of a hue; this can be adjusted by adding black or white.
- Intensity (or saturation): This is how bright or dull a hue is.
What are the colors of the rainbow associated with?
- Heat: Red is often associated with hot temperatures. You will often find that hot water taps have a small red indicator on them to help you to tell the difference between the hot and cold taps.
- Love: This color is often considered very romantic, especially when paired with the classic ‘heart’ symbol. You may see a lot of red on Valentine’s Day, such as red roses or chocolates wrapped in red foil.
- Danger or ‘stop!’: Red means ‘ threat’ on many roads or other warning signs. One of the most essential is the ‘stop’ sign that lets drivers know they must stop driving. Red is also used on traffic lights to tell drivers they must stop.
- Anger: When someone is angry, their face flushes and becomes red.
Color fact: Red was one of the first colors used in Prehistoric art, from a pigment made from ochre.
- Fruit: Unsurprisingly, fruit is the first thing many think of when they think of the color orange. Oranges are citrus fruit known for their tasty juice and for being rich in vitamin C.
- Warnings: Traffic cones are orange in color. Another warning is the amber traffic light signal, which is orange-yellow and warns the driver that they must prepare to stop.
- Autumn: Leaves will often turn varying shades of orange-red during this season. We also think of harvesting vegetables like carrots or pumpkins. Pumpkins remind us of Halloween when seeing this color, which takes place in October every year.
- Fire: the warm glow of a bonfire or fireplace is mostly orange-red; this makes us think of warmth.
- Fish: some of the most famous types of fish, such as koi carp, goldfish, and clownfish, are orange in color.
Color fact: Orange was called ‘geoluhread’ in Old English, which means ‘yellow-red.’
- The Sun: Perhaps the first thing you may consider when considering yellow is sunshine. Yellow is a bright primary color, and many other things associated with yellow, such as blonde hair or buttercup flowers, are compared to the sun so often that it has become a cliché. One flower, the sunflower, is even named after the sun due to its lovely yellow petals. This association with the sun’s warmth is likely why yellow makes many people think about happiness.
- Food: Many delicious foods come to mind when we think about yellow. Ripe bananas, honeydew melons, bright egg yolks, fields full of corn, and creamy butter.
- Spring: Yellow, especially pastel yellow, is considered a Springtime color. Bright yellow baby chicks and ducklings are usually born in Spring, and daffodils bloom in Springtime too.
- Bees: bees (and wasps!) are usually covered in yellow-and-black stripes. Their vibrant color makes them easy to spot amongst the grass in your garden.
- Nature: So many beautiful plants we see are at least partially green. The grass in our garden, the leaves on trees, and even the stems of flowers are all green! It is in part due to the process of photosynthesis. A green pigment called chlorophyll allows plants to absorb sunlight and turn it into energy that lets them grow. This association between green and nature has led to the phrase ‘green thumb.’ Someone is said to have a green thumb if they are a good gardener. Green and images of green leaves are associated with green energy, another name for renewable energy sources such as wind and solar power.
- Emeralds: Emeralds are a kind of beautiful green gemstone. They are used to symbolize a 55th wedding anniversary.
- Envy (or jealousy): Have you ever heard the phrase ‘green with envy’? The color green has historically been associated with envy, with some calling envy ‘the green-eyed monster. This association dates back to the ancient Greeks, who believed jealousy was caused by an excess of bile, which gave the skin a green tint.
- Oceans and the Earth: About 71% of the Earth’s surface is covered in water, inspiring the name of David Attenborough’s famous documentary, Blue Planet.
- Calm: Blue is often associated with feelings of calm and tranquillity; this means it is usually a popular paint color choice when decorating places people want to calm down or relax, such as the waiting rooms at dentists’ offices, hospitals, or therapy/spa settings.
- The Blues: If you are sad, this can sometimes be called ‘the blues’ as blue has long been associated with sadness; this likely inspired the name of the musical genre, ‘The Blues.’ This genre has its roots in the oral tradition of African American work songs, which were sung to help communicate and alleviate the pain of loss and injustice.
Color fact: Blue is said to be the world’s favorite color, usually topping polls and surveys worldwide when people are asked which color they prefer!
Indigo is a spectral color often described as ‘dark blue.’
- Denim: Indigo dye is used to give jeans their traditional indigo color. This dye has two sources: the indigo plant or the woad plant Isatis tinctoria.
- Indigobirds: Male indigobirds are a beautiful, almost-metallic shade of indigo.
- Lactarius indigo: This species of fungi is an indigo-colored mushroom.
- Eastern indigo snake: This snake is named after indigo. It is a dark blue/black color found in the southeastern United States.
Violet is often conflated with purple. Violet is a spectral color, whereas purple combines red and blue light. They are perceived to look very similar.
- Violets: When thinking of violets, many will first think about the beautiful bloom of the sweet violet flower.
- Foods: There are many popular purple and violet foods in nature. Grapes, plums, aubergines, and purple carrots. Despite their name, blackberries and blackcurrants are purple too! Also, violets are edible flowers that can be used as decoration on cakes or other dishes. Their floral flavor is often used in sweet dishes and desserts.
- Luxury: Violet and purple have a strong historical association with royalty and the wealthy, as the purple fabric was previously costly; this started with Roman emperors and continued for centuries. It is also associated with luxury because it is a complementary color with yellow/gold; gold jewelry was often placed on purple fabric or a violet box to make it stand out. Nowadays, purple is often used in the packaging of products to imply luxury. You can probably find many examples of this in your local supermarket, from decadent chocolate biscuits to cosmetics and hair care bottles.