Colour theory

In visual perception a color is almost never seen as it really is – as it physically is. This fact makes color the most relative medium in art.

Albers  Interaction of Color 1963 p1

Our perception of colour depends on both physical factors relating to the way the eye registers light and more psychological and cultural factors that affect the way the brain reacts to and interprets colours and their relationships to each other.

Artists and designers have used and experimented with complexities and ambiguities in interactions between physical and psychological dimensions of colour to portray emotions and question the nature of perception. They may choose to focus on local or optical colour.

Some key implications of colour theory for illustration:

  • Artists may choose to focus on local or optical colour. Or use completely arbitrary colours to impose their own feelings and interpretation onto the image.
  • Tone is perceived first, then colours (yellow first), and then the image. Using flat primary colours will detract attention from the image – making colour the subject and tending towards abstraction of shapes.
  • Optical mixing is inevitable as the brain interprets colours, successive and simultaneous contrast.
  • Consider the effects of using strokes around shapes to increase or reduce colour vibration effects.
  • Precisely replicating colours across different media is difficult (eg RGB and CMYK) and devices (different printers and monitors).
  • It is desirable to allow for individual differences in perception eg colour-blindness or epileptic reactions. Some software allow for simulation of the ways in which images will be differently viewed.
  • It is important to be aware of cultural differences in interpretation of colour depending on ones audience.
  • All these factors affect the relationship between colours and harmony/tension in composition of an image and the ways in which the image as a whole will be interpreted.

Notes on Colour Theory

What follows brings together my notes and experimentation from previous painting, photography and printmaking courses and updates these notes as relevant for this course. See references at then end.

Physical factors

Light

Light consists of rays of different wavelengths. When light strikes a surface, certain wavelengths are absorbed and others are reflected by its pigments. Different combinations of reflected wavelengths form all the observed colours.

Eye to brain

As light passes into the eye it strikes the retina at the back of the eye which consists of layers of cells including:

  • rods – that perceive black and white and allow us to see dimly lit forms
  • cones – that help us perceive hues. The cones in the eye only recognise red (long wavelengths), blue-violet (short wavelengths) and green (middle wavelengths). They relay these colour messages to the cones of the fovea, an area at the centre of the retina, whose cones transmit to the brain.

The brain then assimilates the red, blue-violet and green impulses and mixes them into a single message that informs us of the colour being viewed.

Perceptions of colour vary significantly between individuals depending on eye and brain biology eg degrees of blindness to particular colours, ways in which stimuli pass along the optic nerve etc.

There are many other factors affecting our perception of a colour, such as:

  • the surroundings of the object
  • its surface texture
  • the lighting conditions under which it is seen.

How much of a colour is used, whether it is bright, dull, light or dark, and where it is placed in relation to another colour are also crucial factors in our perception. A distinction is usually made between:

  • local colour: the wavelengths that are reflected by a surface under conditions of white light
  • optical colour: the combination of local colour with light striking it and other surrounding colours

 

Dimensions of colour

Hue
Pure hues: A colour without any black, grey, white or complementary is called a pure hue and occurs in Newton’s light spectrum.

  • Primary colours are those which cannot be mixed using other colours
  • Secondaries the result of mixing two primaries
  • Tertiary colours, the result of mixing secondaries with one of their adjacent secondaries.

Broken hues are the result of mixing these pure hues with their complement to produce browns and greys.

However there is significant variation between colour theorists as to how they identify primary colours, and also between additive methods (RGB used where light is added and where white is the result of mixing all light wavelengths) and subtractive methods (CMYK and pigment mixing as in printmaking or paint where black is the result of mixing all colours). Moreover pigments are rarely pure. The results from mixing also depend on the relative colour temperature of each of the colours being mixed.

Value

The lightness or darkness of a hue, or tone. Pure hues vary in value from yellow (lightest) to violet (darkest) This means that  mixing them will also alter the value. If you squint when looking at two hues of similar value they will merge together. When pigments of equal value are mixed together this gives a darker value because more wavelengths are absorbed and fewer reflected.

Value changes convey texture, are used for shadows and form. Sharp contrasts in value produce the effect of precision, firmness, objectivity and alertness. Close values produce feelings of haziness, softness, quiet, rest, brooding etc. Dark compositions give feelings of night, darkness, mystery and fear. Light compositions of illumination, clarity and optimism. Middle values are relaxed and often go unnoticed.

Discords: when the value of a hue is altered by the addition of black, white or another colour opposite to its natural value order eg adding violet and white to make lavender.

intensity (also termed saturation or chroma) defines the degree of purity or brightness (as opposed to light) or how dull (as opposed to dark) a colour is.

Pure hues are those where there is no black, white or complementary colour added. When pure black or pure white are present they are noticed before the other hues and colours present. Pure hues differ in chroma strength – lighter hues have stronger chromatic strength. Pure hues can be dulled to coloured greys through adding grey of the same value. Or mixing with complementaries to produce a shade.

Neutral greys can be obtained through mixing false pairs – orange and green, green and violet, violet and orange. But they tend to favour one of the parent hues and are less powerful than those made by combining complementary hues. They can also be produced through layering.

Intensity can create effects on objects in space.

  • high intensities make an object seem large and pushes it forward in the visual field
  • light pure values like yellow advance most on a dark background and least on a white background
  • pure hues have a relative strength. if balance is required, they should be used in the right proportion.

Temperature
Temperature refers to the warmness or coolness of colour.

  • Warm hues are reds and secondary and tertiary hues of red (warm yellows, yellow-orange, orange, orange-red, red and red-violet). Warm hues appear nearer to us and are generally more stimulating.
  • Cool hues are blues and secondary and tertiary hues of blue (cool lemon yellows,  greens and bluish violet. Cool hues appear further away and are generally more relaxing.

Cultural factors

Cultural background and experiences affect a colour’s impact.

Factors such as linguistic distinctions can affect perception of colour – in some languages there is no distinction between blue and green and so although people can distinguish when questioned they do not make an immediate distinction.

The ways in which colours are interpreted will vary between cultures and for different groups, and even from individual to individual. Even where colours are perceived similarly, they may mean different things – in Asian cultures white is associated with death. Red is associated with happiness and luck. In Western cultures black is associated with death and white with purity. Red is associated with danger and blood.

Colour associations are also influenced by the types of pigments available and their material value. For example:

  • blue   lapis lazuli for the madonna
  • purple   mollusc in ancient greece so royalty
  • ochres and earth colour
  • red vermillion:  marriage and luck in Asian cultures
  • black: means purity in Islamic cultures
  • white purity. turns away other colours.

Colour harmony

Colour harmonies have conventionally been categorised as:

  • Monochromatic: a single hue with its tints and shades produced by mixing with white, black (or its complement)
  • Analogous: three or more hues that are next to each other on the colour wheel. Analogous schemes are most emphatic when the common hue is primary. They are most harmonious when the middle hue is primary (eg red-orange, red, red-violet rather than orange, red-orange and red).
  • Complementary: colours opposite each other on the colour wheel. But different artists may use different colour wheels, complements are different between RGB and CMYK.
  • Split complementary: a colour and the two colours surrounding its complement.
  • Triad: equidistant on the colour wheel. These result in a dominance of warm or cool.
  • Quadrad: where the four hues are equidistant on the colour wheel.

However in recent years colour choices have become much more varied, partly because of artist experimentation to ‘break the rules’, different cultural influences and also because of the rise of digital software that enable the rapid generation of a range of colour options – for example Adobe colour.

Colour interactions

Itten and Albers studied the interaction between hues and the ways in which our perception of hues and tones is altered radically by the other colours surrounding them. The effects of interactions can be altered by using coloured strokes around shapes.

  • Successive contrast: perception of each colour is followed by perception of its complement as eye and brain adapt – this is seen by staring at a colour for some time then closing one’s eyes.
  • Simultaneous contrast: where adjacent colours interact with each other. Simultaneous contrast is most intense when the two colours are complementary colours.
  • Vibration where certain hues meet: Disappearing boundaries: where analogous hues meet. Dissolving boundaries: where broken hues meet
    This can be used to create mysterious effects. Or combatted using sharp edges.
  • Discords play a supporting role – they are easily overshadowed by colours that are not discorded, but they stop the tendency of hues to spread visually. Large areas in discorded colours should be avoided as they weaken a composition. But small areas reduce monotony. Light discords also produce the best highlights (because they are unexpected and attract attention??) The discord chosen should be based on the primary colour closest to the object featured in the highlight, or the next closest primary on the colour wheel.

When colours or shades of grey are sequenced in a composition leading from light to dark or dark to light then the eye is comfortable. But when the sequence is broken eg grey background, followed by white then black then the effect is jarring eg dramatic skies. El Greco View of Toledo.

Rhythm, repetition and movement

Repeating colours can lead the eye through a composition and create a sense of movement.

Emphasis can be accomplished by using colour in a number of ways

  • colour contrast: bright/dull, light/dark, warm/cool
  • area size: large areas of a colour versus small
  • texture: rough versus smooth
  • use of arbitrary colour
  • unusual detailing
  • contrast with surroundings

Harmony can be achieved through:

  • repetition
  • similarity
  • use of tonality
  • surrounding a colour with a neutral colour

Inspiration

References

Albers, J. (1963). Interaction of Colour. New Haven & London, Yale University Press.

Barringer, T., et al. (2012). David Hockney: A Bigger Picture. London, Royal Academy of the Arts.

Batchelor, D., Ed. (2008). Colour. London and Cambridge Mass., Whitechapel Gallery and the MIT Press.

Britain, T. (2013). Gary Hume. London, Tate Publishing.

Davis, G. (2008). 2000 Colour Palette Swatches : The Designer’s Toolkit. East Sussex, UK, ILEX.

Dobie, J. (1986). Making Color Sing : Practical lessons in Color and Design. New York, Watson-Guptill Publications.

Eiseman, L. (2000). Pantone Guide to Communicating with Colour. Cincinatti, Ohio, GRAFIXPRESS.

Feisner, E. A. (2000). Colour : How to Use Colour in Art and Design. London, Laurence King Publishing.

Gage, J. (1999). Colour and Meaning: Art, Science and Symbolism. London, Thames & Hudson.

Greenwood, K. (2015). 100 Years of Colour : Beautiful Images and Inspirational Palettes from a Century of Innovative Art, Illustration and Design. London, ILEX.

Hornung, D. (2005). Colour : a workshop for artists and designers. London, Laurence King Publishing.

Hudson, T. (2004). Hockney’s Pictures, Thames & Hudson.

Itten, J. (1961). The Elements of Colour. London, Wiley.

Jennings, S. (2003). Artists’ Colour Manual, Collins.

Livingstone, M. (2005). Patrick Caulfield. London, Lund Humphries.

Lynton, N. (2007). William Scott. London, Thames & Hudson.

Parker, A. (2005). Seven Deadly Colours: the Genius of Nature’s Palette. London, Natural History Museum.

Parker, S. (2016). Colour and Vision through the eyes of nature, London, Natural History Museum.

Roque, G. (2009). Art et Science de la Couleur: Chevreul et les peintres, de Delacroix a l’abstraction, Gallimard.

Sausmarez, J. de. (2008). Basic Colour : A Practical Handbook. London, Herbert Press.

Stevens, C. and A. Wilson, Eds. (2017). David Hockney. London, Tate Enterprises.

Wilcox, M. (1987). Blue and Yellow don’t make Green: How to mix the colour you really want – every time. Penrith, Australia, School of Colour Publications.

Zelanski, P. and M. P. Fisher (1989). Colour. London, Herbert Press.

Useful links

Color Matters wide general overview

Cambridge in colour – technical notes on colour perception, colour harmony and colour management for photographers.

Color Art has notes on vision science and art