Complementary colors

Complementary colors are special pairs of colors that, when put together or mixed, cancel each other out to create a gray color like white or black. When these colors are next to each other, they make a very strong contrast and look really vivid. These pairs are also called opposite colors.

Which colors are complementary depends on the color model being used. In modern color theory, using the RGB additive model or the CMY subtractive model, the complementary pairs are red–cyan, green–magenta, and blue–yellow. In the older RYB color model, the pairs are red–green, yellow–purple, and blue–orange. Opponent process theory suggests that the strongest contrasting pairs are red–green and blue–yellow. The pair black–white is common to all these theories.

These differences happen because traditional color ideas have been updated with newer, science-based theories, and because words for colors can be used in different ways. For example, blue can be the complement of both yellow and orange because many different shades, from cyan to blue-violet, are called blue.

In different color models

The traditional color wheel shows pairs of colors that look best together. These pairs are called complementary colors. Examples include red and green, blue and orange, and yellow and purple.

Modern technology, like computer monitors and televisions, uses the RGB color model. In this model, red, green, and blue light mix to make different colors. Complementary pairs here are red and cyan, green and magenta, and blue and yellow.

In theory and art

People have noticed how colors affect each other since ancient times. Early thinkers like Aristotle and Thomas Aquinas saw that colors look different next to each other. In the 18th century, Isaac Newton made a color circle showing colors that are opposites and create strong contrast.

Artists and scientists later studied how to use these contrasting colors, called complementary colors, to make paintings more powerful. For example, Claude Monet used orange and blue in his famous painting Impression, Sunrise, which gave the Impressionist movement its name. Other artists like Vincent van Gogh also used complementary colors to create strong effects in their work.

Afterimages

Further information: Afterimage § Negative afterimages

If you stare at a color, like red, for about 30 seconds and then look at a white surface, you will see the opposite color—in this case, cyan. This happens because the parts of your eyes that see red light get tired. When you look at white light after that, your brain shows you the opposite color. As your eyes rest, this effect will go away. This is one of many interesting things studied in the psychology of visual perception.

Practical applications

Complementary colors are useful in art and graphic design. They make each other look brighter when placed side by side. They are also important in creating eye-catching logos and designing things in stores.

These colors have practical uses too. For example, life rafts and vests are often orange because it stands out well against the blue ocean. Red and cyan glasses help people see special 3D images, making pictures appear three-dimensional.