Sunday, 9 October 2011

Colour Theory

There are two fundamental systems in use to describe primary colours; Additive and Subtractive

The first, Additive, is used to describe the three primaries where combinations of them will produce all the colours in the visible spectrum and where the three primary colours themselves, when mixed equally, will produce white light.  This is the greatest hint of all as to where these colours are found - they are the colours of transmitted light.  The primary colours are Red, Green and Blue (RGB) and they relate particularly to light, digital cameras and displays.  This is illustrated in the figure below.

Subtractive colours are so called, because when the three primaries used in this system are mixed together in equal parts, they produce Black.  A good way to remember this is that if you remove all light, then there is nothing left and "nothing" is typically associated with Black.  In digital terms, Black has the value 0 and White is represented by 255.

Subtractive colours are Cyan, Magenta and Yellow (CMY), as used in printing, or Red, Yellow and Blue (RYB) which are used in painting and in art theory.  In a later section of this part of TAOP, the colour wheel used will be that based on the painters primaries, RYB and their complementary opposites, which are green violet and orange.  In printing, these colours are also referred to as CMYK, where K stands for black, or originally "Key Plate".  The Key Plate, in printing, was that which was used to provide or enhance detail and contrast and was usually impressed in black ink

The way subtractive colours mix is shown in the illustration below.

The figures used above have both been obtained from Wikipedia and have been released into the public domain by their author.

Complementary and harmonious colours.

First of all a simple definition of primary colours, based on that given in the course text.  Primary colours are those which cannot be further broken down into other colours.

I have already used the term "complementary", so probably best to describe here what is meant by this.  Such colours are those which are located opposite to primaries in the colour wheel.  So with the RYB model, green is complementary to red, violet to yellow and orange to blue.  Where such colours appear in a photograph, they create maximum contrast (should I be using this word here as it could be misunderstood) and can create greatest impact.

Harmonious colours are those which are located alongside each other.  Why so called?  That is because there is some harmony between them; I've seen reference to such colours giving a sense of calm and peace, though this does not really equate with the way we see colours, with oranges and reds providing striking and vibrant images, warm looking, whereas blues and greens are cool and therefore frequently regarded as restful. Less saturated harmonious colours, regardless of whether they are "hot" or "cool" produce images which are restful.

TAOP Part Three: Colour

Colour is easily taken for granted.  After all, for most of us, the world is seen in colour, in its many qualities, and we also react to colour in many different ways.  When I was introduced to photography by my parents, the films used were predominantly black-and-white and colour was reserved for "high days and holidays".  Indeed, the reproduction of colour, even to me as a child, seemed very poor, though this might have something to do with the camera used at the time - a Kodak Duaflex 2!  Certainly there seemed to be no objection to viewing the world in monochrome.  50 years on, monochrome is generally regarded as "arty" and colour is the norm.  We even accept that colour can be and is manipulated, particularly where advertising is concerned, or in almost any publication.

For many years we have accepted the way the world is reproduced by artists, whether as paintings or in print.  Here, artists have mixed colours, available as pigments, in order to produce on canvas their perception of how a scene looks in colour.

This part of TAOP addresses the basic properties of colour, learning how to control, alter and modify them in photography and to use them as an element of design.

The use of colour in design, and in particular the psychology of colour is something which is of particular interest to me and I shall be exploring that further in my learning blog.

In this section I have made use of a variety of reading matter, not least making use of that source of all knowledge - Google.  Its amazing how many articles and other works can be found by typing in "psychology of colour" as a search term!  Wikipedia has also made a contribution to my understanding.

To be honest, I almost had too much in the way of references, however these did stimulate my interest.  I was particularly interested in Pantone, and that they had been acquired in 2007 by X-Rite, who produce Colormunki, the monitor and printer calibration system.  I use Colormunki to calibrate both monitor and printer.

From the Pantone web site, I quote: "In 1963, Lawrence Herbert, Pantone's founder, created an innovative system of identifying, matching and communicating colors to solve the problems associated with producing accurate color matches in the graphic arts community. His insight that the spectrum is seen and interpreted differently by each individual led to the innovation of the PANTONE MATCHING SYSTEM®, a book of standardized color in fan format."  The range and interpretation of colour by Pantone, is just incredible, but realistically beyond what I am trying to achieve here.

Delving into the Epson book is again outside the scope of this part of TAOP, more likely to be relevant in the Module "Digital Photographic Practice", however the book contains a lot of images which are great examples of use of design through form and colour and provide ideas and inspiration.

My references for this section include:
  • OCA TAOP course notes - Part three: Colour;
  • Basic Colour Theory - OCA Photography Course Supplement; 
  • Colour, Michael Freeman, ILEX, 2005;
  • The essential colour manual for photographers, Chris Rutter, Rotovision SA, 2006; 
  • Methuen Handbook of Colour, Eyre Methuen Ltd, 1981;
  • Colour, Marshall Editions Limited, 1983;
  • EPSON Complete Guide to Digital Printing, Rob Sheppard, Lark Books, 2008; 
  • Pantone,