Some of the effects I am discussing here are very subtle and you may not be able to see them in the examples I have provided.  We probably need to remember that colour perception differs from person to person and what is obvious to one person may not be so obvious to another.


Ref:     Oxford Companion to Art. Harold Osborne Ed, Oxford University Press, 1970
           A Visual Dictionary of Art. Anne Hill General Editor, Heinemann, 1974  
 
We see objects and surfaces because they reflect light. Therefore we see colour in reflected, coloured light. This means there must be an external light source and out-of-doors this is usually the sun. Indoors it can be any one of a number of artificial lights. Paintings are normally viewed under “white” light. This is light made up of a spectrum or mixture of every colour. The sun provides “white light” as do most artificial white-light sources. 
The colour of light from an artificial source though can vary; for instance the light from a fluorescent source is whiter and colder than that from an incandescent (older style) light bulb. Obviously, varying the colour of the viewing light will change the appearance of reflected colour.
In what follows we shall assume we are dealing with white light, allowing that white light may vary depending on its origin.
 
When viewing paintings we are concerned with the colour of surfaces. Mostly we can not see through the colour we are looking at though sometimes a painter will provide a film for us to look through as in a cloud study. Surface colour takes on the appearance of the surface so can be rough or smooth. Rough surfaces can change appearance when light is reflected from them at different angles. Usually painting surfaces are smooth (but not too shiny), though can be rough when a painter has used an impasto style of painting to build up a surface. Van Gogh used this technique very successfully.
 
Here are some terms we need to understand before proceeding any further:
 
  • Lustre or shine. Surfaces sometimes appear brighter than the actual surface colour: especially in bright light. Lustre breaks up the surface texture and alters its appearance. Very shiny surfaces are usually avoided in painting as the reflected light can be very distracting.
 
  • Metallic appearance.  There can be significant differences between the perceived colours of lustrous and non-lustrous parts of a metallic surface. Including painting of metallic surfaces in a picture thus has attendant risks.  Gold leaf surfaces have been used for at least 500 years in painting and provide an aura of opulence or reverence as well as highly reflective spaces in a picture.  However this poses different problems to those encountered when representing metallic surfaces with paint.
 




Agnolo Bronzino
Italy 1503-72
Duke Cosimo I de' Medici in armour early 1540s
Oil on panel, 86 x 67 cm
Art gallery of New South Wales: Sydney


In this quite wonderful picture by Bronzino note how the colour of the armour changes when it is reflecting light and the darker parts of the armour recede slightly into the picture compared to the shiny, lighter parts.  Bronzino has created these effects with pigment alone. (How lucky the Sydney gallery is to have this Renaissence masterpiece; not only by Bronzino but of his important Medici patron)

 

  • Luminous, or glowing, colour. Luminous objects give off light. Paintings are never luminous as they can only reflect light. Paintings can appear to be luminous and to give off their own light but this is an illusion created by the artist. Rembrandt was an expert at creating apparently luminous parts in his pictures.




Rembrandt
Flemish 1606-69
Two Old Men Disputing
Oil on wood, 72 x 60 cm
National Gallery of Victoria, Melbourne


Here we see Rembrandt painting light.  The area to the lower right in this masterpiece appears to give off its own light.  We are of course seeing a reflection of light coming in from our left and we are viewing this reflected light by a further reflection from the surface of the canvas.

 
Part of the artist’s trade is to create the illusion of lustre, luminosity or metallic appearance in surface colour. This is done solely with paint which has none of these qualities. Much of the pleasure in viewing a picture comes from being part of the illusion that we are looking at a surface which has these properties but is created on a flat surface with pigment alone.
 


Colour has three fundamental variables: hue, saturation and brightness
 
  • Hue. This describes what we might call the “actual” colour. Is it red, blue or what is it? Colour varies from red through yellow to green and blue. We can combine colours to produce different hues and there are about 150 possible variations. There are more variations at the red end of the spectrum or range because we have greater discrimination when the wavelength of the light wave is increased as it is at the red end of the spectrum. Waves at the blue/violet end have shorter wavelength than waves at the red end and we see fewer variations (different colours) at the blue end of the spectrum. The colours which we see as having the greatest differences from each other are blue, green, yellow and red. These are sometimes referred to as the primary psychological colours- not to be confused with primary physical colours; red, yellow and blue, more about them later.


 

Andre Derain
French, 1880-1954
Bridge over the Riou,
Oil on canvas, 83 x 102 cm
Museum of Modern Art, New York


In this Fauve picture by Derain we see him using plenty of different hues (colours); mostly colours close to the primaries highlighted with black.

  • Saturation. This describes how pure a colour appears when compared to a non-coloured surface of equal brightness. It corresponds roughly to how much colour is on the surface.


 

Marc Chagall
French born Russia, 1887-1985
I and the Village, 1911
Oil on canvas, 192 x 151 cm
Museum of Modern Art, new York


In this mystical masterpiece Chagall uses saturation differences to enliven the two prominent heads and the red-white panel leading us into the picture. 


  • Brightness. Brightness or lightness describes the same colour on a scale running from dim to bright. Thus one might describe a blue as “bright” or “dim” (subdued or dull). “Tone” refers to differences in the apparent lightness of colour under the same lighting. “Traditional” painting styles rely heavily on tone to illustrate surface difference, shape and even relative position.  More about tone shortly



 

Rembrandt
Dutch, 1606-69
Self Portrait,
Oil on canvas, 134 x 104 cm
The Frick Collection, New York

Here is Rembrandt at his tonal best.  Note how he creates the shape, hang and general appearance of the man's clothing by simply changing the tone of the same colour.


All colour can be described as a combination of hue, saturation and brightness. These three are the roots of colour description as parts of speech; nouns, verbs etc are the roots of language.

 
Here are more terms used to describe colour. You will see that each is a combination of our three roots
 
  • Brilliance. A term which combines saturation and brightness but not hue.  Thus One might refer to a "brilliant" blue.
 
  • Chromatic Quality. A, quite rightly, underused term which describes a combination of hue and saturation but not brightness. 
 
  • Tone. Tone, tonality, tonal value or tonal quality are terms which are variously and confusingly used to describe changes of hue and brightness within an art work. There are clearly differences in tone within works by Rembrandt and, most obviously, Caravaggio where differences in brightness are applied to the same colour (hue). An art movement in Melbourne started by Max Meldrum used tone to the exclusion of other painterly techniques to construct pictures however Meldrum’s movement was ultimately seen as too narrow to be included in serious teaching on painting technique. Nevertheless tonal differences in pictures have been, and still are, a vital part of composition. We need to be careful when we talk about tone to be sure that we are referring to differences of brightness within the same hue. The best way to view tonal values in a picture is to view it in black and white, a process made easy by the advent of computer software such as Photoshop. I have done this in the picture below and you can see how Rembrandt has lightened and darkened the same colour to achieve the moulding of the figure. 






 
  • Shade. Not to be confused with ‘light and shade’, shade is a term to be avoided as it is ambiguus and confusing. We may talk of shades of colour- “that’s a nice shade of blue”. In this context the term shade is best kept to discussions of house painting rather than fine art. ‘Shade’ would seem to combine all three of our roots, hue, saturation and brightness and is therefore unnecessarily complicated, vague and unhelpful.
 
  • Tint. Tint is most useful when describing the addition of a small amount of pigment to produce subtle variations of hue and saturation. Descriptions of long-light painting at the start and end of day can often usefully include the word ‘tint”.


 

Duabigny
French, 1817-1878
Dieppe, 1887
Oil on canvas, 67 x 101 cm
The Frick Collection, New York

Daubigny has added small amounts of colour to the sky in this picture to achieve the sensation of changing, subtle light in early morning or evening.


  • Intensity. Usually it is best to say saturation when we are tempted to say intensity. However the word has significant use when referring to the apparent lift or subordination produced in a colour caused by its juxtaposition to another colour. As we shall see later placing certain colours side by side can produce different perceptions of one or both even though no change of hue has been made.

 
Primary, Secondary and Complementary Colours

The descriptions ‘secondary’ and ‘complementary’ are often confused by careless writers. 
 
  • Primary Colours. In painting these are red, blue, and yellow (different to those of physics which restricts itself to combining coloured light). A primary colour can not be made by combination of either of the other two primaries. All colours (hues) are made by differing combinations of primary colours. 

 

Primary Colours


  • Secondary Colours. These are colours made from combinations of two primary colours.  There is a very large number of secondary colours. 
 
  • Complementary Colours. These are colours on opposite sides of a colour wheel. There are two variations of colour wheel. The most useful is the one shown here where the circumference is divided into equal segments but this does mean that the primary colours are not on opposite sides of the circle; green and blue are almost next to one another because there are far fewer combinations of blue and green than of red with the other two. Complementary colours produce the greatest intensity differences when side by side. In the colour wheel variation where primary colours are placed opposite each other green and blue and their combinations must occupy larger segments, since there are fewer of them. This may lead to the assumption that they are more important than other hues.   The first type of wheel is illustrated here.

 


 Colour Wheel (From The Oxford Companion to Art)

 
Perception. Perception of colour is a human response and a variety of psychological terms has come into use to describe colour. We must keep in mind that any of these derivative terms is simply a combination of the three roots; hue, saturation and brightness. 
Psychological descriptions are often very helpful when describing colour. Here are some terms and phrases you will find in art literature:
 
  • Warm and Cool Colours. Warm colours involve red and yellow combinations and lie in the orange part of the colour wheel. Warm obviously refers to the relation of these colours to sunlight and the light and warmth from fire. Cold colours lie in the blue section of the wheel moving towards green. Clearly colour warmth is related only to hue.

 

Warm and Cool Colours


Advancing and receding colour. Warm colours seem to come forward in a picture whereas cooler colours in the same plane appear to sink back into the picture plane. This is a device much employed by landscape painters who will show a range of hills or mountains in receding colours to convince us that we are looking into the picture and that it has depth.




 

Advancing and Receding Colour (from the Oxford Companion to Art)

  • Weight. Dark colours appear heavy, both physically and emotionally. Light colours suggest weightlessness or lighter emotions.
 
  • Size. Lighter coloured objects can appear larger, and therefore closer, than darker-coloured objects of the same size. Still life pictures may exploit this.
 
 

Goya
Spanish, 1746-1828
Dona Antonia Zarate, 1805-6
Oil on canvas, 104 x 82 cm
National Gallery of ireland, Dublin

Goya has used few colours in this picture and featured black.  The expanse of black encourages us to see the subject as a person of substance whilst the lighter flesh tones bring the features out of the picture and illustrate the likeness perfectly.  Having the folded arms in front of the black garment creates the illususion of bodily form in the figure.  The facial expression is sombre- reinforced by the black- and perhaps the woman has had bad news or is in mourning. Note how the cleverly placed fan coming out of the picture further reinforces the paintings depth and balances the darker mass of the shoulders above.


Up until early in the 20th century colour was used simply to indicate what objects were being viewed, daffodils were painted yellow because that is the natural colour of daffodils and is immediately recognisable. Modern art changed all that. The advent of the Fauve movement in particular started a focus on colour as indicator of emotion and personality and colour-field painting later in the century focussed almost entirely on the properties of colour as the reason for the painting’s existence. 
 
The focus of this essay is on colour but it is worthwhile noting that in the creation of an art work colour is just one of the tools available. Design or composition drives the overall plan.
 
I said earlier that we see objects by reflected light. We need to take this idea a little further to explain colour vision and understand some of the techniques used by modern and contemporary painters.
White light (from the sun or a light source) is made up of all colours of light mixed. Rainbows split white light into its colours and in the rainbow we see constituents of the white light. If any of these colours is selectively absorbed then the remaining colours will make up the final colour we see reflected. Thus an object which appears red will have absorbed all colours from the spectrum except the reds and we see it as red because the light coming to us from the object is red light. This is a subtractive process.
 
Artists mix pigments. Clearly, the more pigments in the mixture the more colours of light will be absorbed. This is why if you mix play dough or plasticine of varying colours the result is grey. Grey is the absence of most colours rather than a colour in its own right- grey results from the absorption of colours. Pure, dark, velvety, black results from the absorption of all colour and therefore of all light; no colours are reflected from a black surface and we only see it because of its surroundings, for instance a frame, and because it blocks our view of something our brain has told us is behind it. Care is needed when mixing pigments to see that the final result is not too restrictive. 




Ad Reinhart
American, 1913- 1967
Abstract painting, 1963
Oil on canvas, 152 x 152 cm
Museum of Modern Art, New York

Reinhardt's picture illustrates perfectly the effect of removing reflected colour.  Look deeply into the picture and you will see varying dark greys and pure black itself.  Looking at the pure black in the centre of the picture gives the impression of sinking into an infinity of depth. 

 
The Impressionists and Pointillists used colour mixing as their main means of producing the oscillating (changing colour and position) affects we see in their pictures. The Pointillists in particular used pigment mixtures applied in small dots or dashes to produce colour mixing which from a distance produced a different colour, but each colour retained its identity on closer inspection of the picture. It is interesting that this invention only appeared in the 20th century when Isaac Newton had showed that white light was a mixture of colours and explained the subtractive idea in the 17th century. Presumably ideas as to what constituted art meant that colour experimentation was unwelcome until much later. Indeed both the Impressionists and the Pointillists were forced to defend their techniques before they became accepted in the 20th century!
 



Monet
French, 1840-1926
Grainstacks (End of Summer), 1890-1
Oil on canvas, 60 x 100 cm
The Art Institute of Chicago

The Chicago Art institute has a number of these impressionistic masterpieces by Monet.  To create the effect of light playing on various surfaces he has placed small patches of colour side by side and our eye (brain really) mixes these colours to produce the effect of reflecterd light showing the form and texture of the surface.  Monet chose haystacks as his subject in these pictures but his aim was to show the effects of light at various times of the day.  At the Chicago gallery you can see several hatstack pictures, painted at various times of the day and in different seasons, exhibited together.  This is the best way to see them as it becomes immediately obvious what Monet was trying to do and that he suceeded brilliantly.  Part of the problem encountered by early critics of these pictures related to their inability to see the colour mixing and simply see the individual colours themselves. 





Georges Seurat
French, 1859-1891
A Sunday on La Grande Jatte (detail), 1884-6
Oil on canvas, 208 x 308 cm
The Art Institute of Chicago

Seurat invented the Pointilliste style.  Rather than patches of colour the picture is made by juxtaposing small dots of complementary (usually) colours.  The correct choice of colours juxtaposed creates the appearance of form and tone as our brain combines the mixture to produce the  expected reflected light.  Using small dots also has the effect of producing blurred outlines further adding to the interest in the picture. 


Matte and Shiny surfaces
How light behaves when it strikes a surface influences how we see the reflected light and therefore the surface. When we see a surface, we are looking back along light rays which have been reflected off the surface after arriving on the surface from the source. Rough surfaces seen close up have many reflective planes thus when light strikes a rough surface the reflected light will be bounce off in many directions leaving fewer for us to see.  We see such surfaces a matte or non-shiny and usually less saturated in colour. Conversely if a surface is flat the reflected light will not be so badly fractured and most of the light rays which arrived from the source come to us after reflection. We see these surfaces as shiny. 
Deciding the surface qualities of a picture is an important decision in painting as it determines the subsequent shininess of the various surfaces in the finished work.
 
The juxtaposition of coloured areas in a picture can change our perception of the colours of one or both areas. Importantly this can be due to perceived changes in hue, saturation or brightness either separately or in concurrent combination of any two of the three or all three. Here are four observations:
 
  • Adjacent areas of high and low brightness appear more and less bright respectively when adjacent than when viewed individually.  

     

    The same colours separated and adjacent

    Note how the yellow appears brighter and the dark green darker when they are side by side than when they are separate.  These are subtle changes but can become significant when large areas of colour are adjacent.  You can see the effect best by looking at the yellow.  The same colours were used in each pair.

     
     
  •  Saturation appears to vary depending on the colour of the background.  
 

 (From The Oxford Companion to Art)


Note how the pink appears much more saturated against the complementary green.  Both pinks are the same colour.


  • Adjacent hues seem to differ more from each other when adjacent than when the hues are viewed separately.  We might simplify this and say that colour can appear to change when the colour is placed adjacent to another colour, brightness being constant.


 

The same green and brown appear to be slightly different when juxtaposed.  The green appears less saturated and the light brown more saturated.


  • Complementary hues seem more saturated when adjacent than when separate
 

Edouard Manet
French, 1832-1883
The house at Rueil, 1882
Oil on canvas, 93 x 74 cm
National Gallery of Victoria: Melbourne

Manet has placed the complementaries yellow and blue side by side to highlight the yellow which now blazes with reflected sunlight.  If you block the blue with a lighter colour, the yellow reduces in brightness.  Readers familiar with photoshop-type software can copy the picture and try the effect out for themselves.


  • Greater contrast in brightness reduces contrast in hue or colour. Thus painters interested in colour effects in their pictures avoid high contrasts in brightness. Conversely artists using saturation and brightness as the main variables in their pictures use a limited range of (stronger) colours.
 

El Greco
Spanish, 1541-1614
St Jerome, 1590-1600
Oil on canvas, 111 x 95 cm
The Frick Collection, New York

Here El Greco wishes to emphasise the gravitas of his subject so uses a varying saturated red against a formal, heavy black background.  The only other colours in the picture are white in the sleeves and flesh tones on the hands, the lighter colours helping to establish depth in the picture.  Using a limited range of colour means that El Greco can show the red cassock with bright areas without having the varying brightness change the contrast in nearby hues.


Spatial Factors
Pictures take up space and depict space no matter in how limited a fashion. Here are some ideas relating to the effect of varying spatial aspects of pictures
 
  • Larger areas appear brighter and more saturated than smaller areas of the same hue or colour. However a small bright area appears brighter within a larger darker space than it would on its own.
 

Goya
Spanish, 1746-1828
Don Pedro, Duque de Osuna
Oil on canvas, 113 x 83 cm
The Frick Collection, New York
 
This masterpiece dominates its space at the Frick museum.  Note how the bright face, hands and vest spring out of the picture because of Goya's use of black in the background and clothing.   



 
  • Sharp outlines enhance brightness, saturation  and apparent size.  This is shown very well in the illustration below.  All lines are the same thickness and colour but both line colour and thickness appear to change with varying colour and strength of outline. 
 

(From The Oxford Companion to Art)


If you look back to the Chagall picture earlier you will see that Chagall has outlined parts of the picture to enhance them. 

  • Shapes hold their shape in pictures despite variations in background. Thus an elephant will still look like an elephant even if various parts of it are superimposed on different backgrounds in a picture.
 
Local Colour and Colour Constancy
Of great psychological interest is the way we tend to view the colours of familiar objects. Generally we see familiar things (casually) in the colours we are familiar with. Thus a piece of fruit in a picture will be viewed casually by an observer as having the same colour which he or she associate with that piece of fruit viewed in normal daylight. If an observer is alerted to expect different colours to those usually perceived then of course they will see the colour as it is. This Local Colour or Colour Constancy influences how painters show colour. Realist painters tend to paint objects and surfaces in the colours which we expect them to be, whereas the Impressionists would paint the exact light reflections which they saw. This caused some confusion when Impressionist pictures first appeared. 
 
 
Light can fall on an object or surface after being reflected from another surface, rather than coming directly from the source Thus a dark colour in bright sun may appear brighter than a lighter colour in shade. This can produce a range of colours and, particularly, brightness which is difficult to reproduce in a painting, particularly a “realistic” picture. Painters prepared to abstract what they see are less troubled by this phenomenon. 


 

(When I re-discover this picture I will tell you who painted it etc!)

Notice in this picture how the brightly-lighted parts of the dark shawl appear a lighter colour than the darker parts of the face despite the face naturally being a lighter colour than the shawl.


So in summary:
Picture qualities can be explained using three fundamentals; hue (colour), brightness and saturation. 
Illusory techniques are used to indicate shape, distance and prominence and these techniques may be used in realist or abstract pictures.
Many other useful terms apart from hue, brightness and saturation are used to describe colour in pictures. All descriptors have as their basis the three fundamentals. 
The psychology of viewing colour needs to be understood by painters and perceptive viewers.

Finally, viewing art can occur on many levels. 
We can simply see the picture as a pleasing arangement of colour and shape especially if it is of a familiar subject.  This type of viewing is the most commmon and often provokes the comment; "that's a nice picture".
We may choose to find out more about the artist and the style with which the picture is created.  We are thus in a position then to judge the picture as a good example of the style or otherwise.
We can find out about technique and effects like those discussed in this article to yield a more complete understanding of what the artist is trying to achieve.  Making this effort allows us to identify more closely with the painter and become part of the creative process ourselves. 
The more effort we make to understand a picture, the greater our appreciation of it.  We also become more able to distinguish a true work of art from a picture which is simply representational.  

JRT
July 2010