I presented the society's illustrated lecture in July. The general consensus seemed to be that, if I chose something so complicated, I should provide the write up andillustrations too!
We looked at the nature of light and the spectrum seen in a rainbow or prism. Newton's description of seven colours was a religious rather than a scientific statement. Most people see a continuously changing colour that ranges from red to blue with a hint of violet beyond blue, and do not feel the need to include indigo. Purple is not the same as violet and is not a colour in the spectrum. We see it only when there is a mixture of red and blue light. If we regard purple as a colour, we should logically also include white, grey and black as colours - after all you can buy them in pencils and paints. A colleague lent me some slides that illustrate types of colour blindness. A member of the audience amplified this with his own experiences of red-green colour blindness. You cannot beat a real witness account and I am grateful for his courage. He draws rather than paints.
Colour needs to be described in terms of hue, saturation and value. There are many ways of doing this. They allow some understanding of why mixing paints is difficult, and the concept of primary colours is not quite right. Similar models show how the range of colours that can be handled by cameras, computer screens, printers and the human eye vary. This is one reason why pictures of painting sometimes disappoint, and also makes it difficult to give a talk on colour using a computer display.
I ended with some demonstrations of optical effects that artists employ, which seemed to be what people enjoyed most. Some are reproduced on the back cover. The three grids of squares illustrate the Bezold effect. The reds and blues are the same in each case, but the introduction of a thin black border makes
the red and blue look darker, whereas a white border makes them appear brighter. The white, green and blue illustration was an idea of my own. These three rectangles have grey shading added with a very simple computer program. Everyone saw this as a white cylinder however, even though there are no ellipses at the top and bottom. This shows how our perception of colour is altered to create a sense of
form. The white is then known as the local colour of the object.
Researching this topic led me to some interesting books. The most practical for an artist is “Colour: How to Use Colour in Art and Design” by Edith Anderson Feisner. 2nd Edition pub Laurence King Publishing Ltd 2006. ISBN 1 85669 441 0. I also enjoyed “Colour:Art & Science” eds Trevor Lamb and Janine Bourriau pub
CUP 1995. ISBN 0 521 49645 4 hardback 0 521 49963 1 paperback. This is from a wide ranging series of lectures at Darwin College in Cambridge University with contributions from Bridget Riley and John Gage amongst others.
Anyone with internet access should visit www.handprint.com which contains one of the world's best references on all aspects of water colour painting including colour theory. The section on Shakespeare's sonnets is also good. Practical recipes for mixing colour, for inexperienced artists like me, are shown in the “Pocket Palette” series from Search Press. I own “The Oil Painters” version (Rosalind Cuthbert 2000, ISBN 0 85532 941 6) and “The Acrylic” version (Ian Siddaway 2002, ISBN 0 85532 997 1). There are several others.
Finally, I could not have given this talk without a modern projector and I am grateful to the society for purchasing one for this and future talks. I am particularly grateful to John Taphouse who put in much hard work on this and in solving the inevitable teething troubles.
Adrian Fowle