Complementary Colours in Art: How Painters Make Colours Glow

Complementary colours are colours that lie opposite each other on the colour wheel: red and green, blue and orange, yellow and violet. In art they are used to make colours glow, because two complementary colours intensify each other when placed side by side. Mixed together, they instead cancel each other out and become greyish brown. Delacroix, the Impressionists, van Gogh and Matisse deliberately built their pictures on such pairs.

Facts

The colour wheel and its opposites

The colour wheel that painters traditionally use has three primary colours: red, yellow and blue. Mix two of them and you get a secondary colour: orange, green or violet. Each secondary colour lies opposite the primary that is not part of it. Orange is made of red and yellow and sits opposite blue, green opposite red, violet opposite yellow. These are the complementary colours.

The word complement means completion: together the pair contains all three primary colours. That explains both of their properties. Side by side they give the eye the whole spectrum and seem stronger. Mixed on the palette they cancel each other out and produce a grey or brown tone – an old trick for muting a colour without using black.

Why they glow: simultaneous contrast

If you stare at a red patch for a while and then look at a white wall, you see a greenish afterimage. The eye tires of one colour and produces its opposite. The same thing happens all the time when we look at colours side by side: each colour pushes its surroundings towards its complementary. A grey square on a red ground looks greenish, on a green ground reddish.

The chemist Michel-Eugène Chevreul, at the Gobelins tapestry works in Paris, described the phenomenon in 1839 as the law of simultaneous contrast, after the weavers had complained that the colours in the patterns changed. As early as 1810 Johann Wolfgang von Goethe had written about the opposition of colours in his theory of colours. The explanatory illustration further down shows the effect: two squares of exactly the same colour that look different. See also the section on colour in Looking at Art.

From Delacroix to the Impressionists

Eugène Delacroix was one of the first to use complementary colours deliberately. He put green shadows in red fabrics and violet ones in yellow, so that the colour vibrated, and his notes show that he studied the contrasts closely. The younger painters learned from him.

The Impressionists almost entirely stopped using black in shadows. A shadow on snow could be blue or violet, because it stands against warm, yellow sunlight. In Monet's Impression, Sunrise of 1872 the sun is a dab of orange against a blue-grey sea and a blue-grey sky, and it is the contrast that makes it glow, even though it is almost as light as its surroundings. Georges Seurat took the principle furthest with pointillism, in which dots of complementary colours lie side by side; see the guide to pointillism.

Van Gogh and the Fauves

Vincent van Gogh wrote in his letters to his brother Theo about how he wanted to use the contrast between complementary colours to express feelings, and about how in The Night Café in 1888 he set red and green against each other to portray the dark passions of humankind. In The Starry Night of 1889, yellow and orange stars and a moon shine against a deep blue sky; see the guide to The Starry Night.

Henri Matisse and the Fauves went even further and let colour break free entirely from reality. In Dance of 1910, five red figures dance in a ring on a green hill against a blue sky. With only three colours the picture gains enormous energy. Read more in the guide to Fauvism.

Colour theory in schools and design

In the 20th century colour theory became a subject in the art schools. At the Bauhaus, Johannes Itten taught colour and form from 1919, with a twelve-part colour wheel and exercises in contrasts: light against dark, warm against cool and the complementary contrast. His book Kunst der Farbe of 1961 is still in use. Josef Albers, who also taught at the Bauhaus, showed in Interaction of Color of 1963, through simple exercises, how the same colour can look completely different depending on its neighbours; see the guide to the Bauhaus in the design section.

Complementary pairs are everywhere in what we see every day. Posters, packaging and signs use them so that something is visible from a distance, and photographers and film-makers like to set warm skin tones against a cool, blue-green surround. It is the same principle that Delacroix and van Gogh used: a colour is at its strongest next to its opposite.

Seeing complementary colours for yourself

When you stand in front of a painting, look for the pairs. Is there a red detail in a green landscape, an orange boat on blue water, yellow flowers against violet shadows? Often that is exactly where the eye comes to rest. Notice, too, where the artist has mixed the complementary colours: the muted, warm greys of a Rembrandt background are often built this way.

On each work's page in the app you can unfold a colour wheel with five colours from the picture and see how they relate to one another; try it with The Starry Night, Impression, Sunrise and Dance. Note that colour pairs look different in light than in pigment. On a screen, where light is mixed, red and cyan, green and magenta, and blue and yellow are complementary colours. The painter's wheel and the physicist's are two different models. Read on in the guide to Impressionism.

How to recognise it

Exercise

Which colour is complementary to blue on the painter's colour wheel?