Applied Painting Theory and Techniques

07 Feb 2023

Colour Theory

Seeing colours

Every time we stop to admire the beauty of our world, we admire its colours. 

Colours influence our perceptions; they recall our sensations and memories. They can be joyful or sad, they make us feel thoughtful, they evoke excitation or give us peace, they make us suffer and they heal. 

Colour is just an optical illusion; it is about our brain registering how different objects reflect rays of light. Sunlight carries all spectres, a whole rainbow of colours, which are partially absorbed and partially reflected by an object; depending on the object’s chemical or molecular structure. Those objects, that absorb sunlight completely we see as black; and those that fully reflect it, we see as white. But most of the objects reflect light in different ways and proportions, and we see them in every different existing colour. 

It’s important to understand that colour is just our optical illusion; there is no static colour, no “green grass”, “blue sky” or “white snow” – the colour of each of these objects changes in the differences of light. Sunrays in the daytime give objects their “normal” original hue; sunsets, moonlight, or electric light change objects’ colours dramatically; and, what is important, objects reflect a light (a colour) of surrounding them objects. 

Colours change underwater; colours change in a fog; colours also change with distance (see art. « Aerial perspective »).

As for an artist, your task is to understand what has struck you in an observed scene; what colour combination, colour harmony or colour domination made you admire the beauty of the moment. And then, having seen and understood, you will need to be able to reproduce the beauty in every its flickering change, on a canvas. Thus a colour study – a colour theory – is an essential part of the development of your own “artistic eye”. 

Some artists are so natural, that they make incredible artwork just by observing the scene and picking up the necessary colours in their palette; others need to refer to special art tools and painting references. The truth is that “natural” artists, who find colour harmonies basing on their intuition and sense of taste, have developed this ability after long years of practice, searching for colour combinations in every their masterwork. 

To approach this sacred knowledge easily, we can start by studying a tool, called “a colour wheel”.

Colour wheel

A colour wheel is a rainbow colour range, presented in circular form, which opposes warm and cold colours. This tool serves to understand the visual relationship of colours, in order to create a contrast or harmony in your painting, as well as to create a proper colour mixture. 

The first model of the colour wheel was invented by Isaac Newton in 1666; since medieval times the colour wheel for an artist has been of the same importance as the periodic table for the chemist. 

Primary colours

The colour wheel represents three primary colours (red, blue and yellow) and all their colour mixtures. 

Red, blue and yellow are called primary, as they are the only colours that cannot be created by mixing other colours; and these colours are used to create all other existing colour combinations (exactly as in the RGB colour model of your computer). 

Theoretically, with these three colours only, you can reproduce all surrounding you reality. But in practice, it is not always possible to achieve every desired tone of colour with red-blue-yellow only, as the pigments of paints have certain limitations. With different blue or red colours, you can get completely different purple – shiny eggplant purple, reddish plum purple, clear lavender purple or even some muddy brownish purple. This is why an artist needs to have more than three colours in his/her/their palette to create desired intense and pure mixtures. 

(Interesting: if you mix all three primary colours, you will get brown!)

Secondary colours

You get secondary colours by mixing 2 primary colours together: 

Red + Blue = Violet

Red + Yellow = Orange

Blue + Yellow = Green

Colours’ relationship

The placement of colour in the colour wheel gives us information about the visual relationship it has with other colours. 

Complimentary colours

The colours that are opposite on the colour wheel are called “complimentary”. They create a full deep contrast, highlighting each other.

For example, if you use a point of red in the field of yellow-orange grass, it will have a very subtle presence. But try to put it in a green field – and it will start burning. The same rule works for yellow with purple, blue with orange, etc. 

Vincent Van Gogh, Terrasse du café le soir

Claude Monet, Les Coquelicots

Johannes Vermeer, The Milkmade

(Interesting: if you mix any couple of the complimentary colours, you will get brown, again! 

And If you add more bleu to your mixture, you will get a grey or even black!.. I always create my own black colour for a marine oil painting by mixing ultramarine blue and burnt umber.)

Analogous colours

The colours that are close to each other on the colour wheel are called “analogous”. You apply them in your painting when you want to create a uniform scene, without a strong contrast. 

Claude Monet, La Femme à l'Ombrelle

Triadic colours

Put an imaginary triangle into your colour wheel, and you will find triadic colour combinations. Being used together in your painting, they create an obvious and rich contrast.

Vincent Van Gogh, Les Iris

Split-complementary colours

Do you need more contrast, but less evident than complimentary (orange/blue or yellow/purple)? Try another triangle, which will show you split-complementary colours. 

The best use of the scheme is to take two nearby colours as a dominant, with one opposite for a contrast; or one colour as a dominant, with the two others as a contrast. 

Vincent Van Gogh, Saules têtards au soleil couchant

Salvador Dali, Rêve causé par le vol d’une abeille autour d’une grenade

Tetradic colours, square colours

More geometrical forms – more combinations! You can get some nice colour harmonies and well-balanced contrasts if you apply a rectangular or square shape to the colour wheel. 

Andy Warhol, The Campbell Soup Can

What is missing in the colour wheel? Where is pink???

The colour wheel deals only with hues – original, saturated colours. 

But the same colour can approach the achromatic palette (white-grey-black), losing its saturation. 

Here is some necessary vocabulary:

  • Hue: the hue is the original pure colour.
  • Tint: tint of a colour is created by adding white. For example, pink is a tint of red!
  • Shade: shade is created by adding black, to darken the colour.
  • Tone: tones are created by adding grey to the colour.
  • Achromatic: achromatic colours are those that do not have a hue: black, white and grey.

Marina Bogacheva

This was my interpretation of a basic colour theory, with some examples of colour relationship used in classical art masterpieces. 

You will find more information about practical application of colour theory in oil painting in the articles "Colour harmonies", "Mixing colours", "Colour Values", and "Aerial perspective". 

© Bogacheff Marina. France, Switzerland. 2023

A contrast of complimentary colours in Van Gogh paintings: 

Vincent Van Gogh, Champs de blé aux corbeaux

Nous avons besoin de votre consentement pour charger les traductions

Nous utilisons un service tiers pour traduire le contenu du site web qui peut collecter des données sur votre activité. Veuillez prendre connaissance des détails et accepter le service pour visualiser les traductions.