I remember well, during a cycling holiday in Ayrshire in Scotland, coming across a famous (but unknown to me) stretch of road called the Heely Brae. As all my senses told me that the road was on a downward incline, I sat back in the saddle, expecting to freewheel down the slope. Instead, I found that I quickly came to a stop and had to resume pedalling in order to reach the bottom!
The illusion was created by an unusual relationship between the contours of the adjoining hills and hedgerows. Illusions are also common in colour perception, notably in the phenomenon called ‘simultaneous contrast’, in which the appearance of a particular area of colour is greatly altered by changes in its surroundings.
This effect is of practical importance in fashion and textile design as well as in graphic design. The relationship of text colour to background colour is also important to ensure legibility. The colour of ambient lighting can also have a significant effect on the way we perceive colour; many readers will have experienced the mysterious change in colour undergone by a sweater wrapped under the fluorescent lights of a store and later unwrapped in daylight!
As individuals, not only do we vary in our description of colour, but our perception of colour is influenced by experiences, memory, and even, research tells us, by the use of hallucinogenic drugs. Research has also shown that certain colours and types of lighting can effect us subliminally. We describe some colours as ‘slimming’ and some lighting as ‘flattering’.
We are apparently soothed by a green environment and excited by red, but feel welcomed by a combination of red and yellow, as patrons of MacDonald’s will know. For average members of the population, differences in how we perceive colours don’t seriously affect our lives.
In some members of the population, however, defects in the retina or in other nerve portions of the eye can cause colour blindness. Dichromatism – partial colour blindness – is manifested by the inability to differentiate between the reds and the greens or to perceive either reds or greens.
Dichromatism is a hereditary condition which affects as many as seven percent of the male population, but a much lower percentage of females. In the realm of commercial printing, differences in colour perception may determine the success or failure of a print job. B