Theories behind color perception have been a topic of debate, for many years. But new studies suggest several possible reasons for the perception of shades of colors.
CNN News recently reported that among scientists, it is a popular belief that color vision is generally consistent within many cultures and populations. It is further believed that evolutionary reasons are responsible for such consistencies.
Within the human retina lie six to seven million photoreceptors known as cones, which allow us to see colors corresponding to short, medium and long light wavelengths. Hues of purple and blue are located at the short end, while hues of red correspond to the long ends. Some estimates claim that these cones allow the naked eye to distinguish between one and ten million variations of colors.
But some people really don’t see the color red in the way that most do. About 8 percent of men have trouble differentiating between certain colors; less than 0.5 percent of women have this problem, according to the American Academy of Ophthalmology.
In most cases of color blindness, the cone systems for either medium or long wavelengths do not work properly, resulting in reds, greens and perhaps yellows appearing very similar. But different people experience this to varying degrees. In rarer cases, people have trouble telling blue and yellow apart; the rarest of all make people see the world in grayscale.
Mark Changizi, a cognitive scientist at the Rensselaer Polytechnic Institute located in Troy, Ney York, states that:
“Color vision is all about emotions and moods, and it has much deeper and richer connections to the rest of our perceptual worlds…”
But Stephen Palmer, professor of cognitive science at the University of California, Berkeley has a different theory:
“I don’t think that we have a pure sensory experience of the color. I think it’s overlaid with how much we like things…”
Some theories suggest that color visuals have only evolved to serve as a survival skill for animals. Although cats and dogs are colorblind, they have better developed peripheral vision. Pigeons and goldfish are able to see ultraviolet light which is invisible to the human eye. Color perception is believed to have developed within the human ancestry to distinguish between red berries and green foliage.
Despite various theories regarding development and evolution, Mr. Changizi’s research suggests that the cones in our retinas are optimized to recognize changes within the hemoglobin located in our bloodstream. Simply, when physiological changes occur, the human eye is able to detect and recognize them in consistency with the color spectrum. His research further suggests that color perception must be consistent, considering the mode of the eye’s cone’s ability to detect subtle skin tone changes.
However, Mr. Palmer’s research suggests differently – that color perception is related to one’s likes and dislikes. For example, the research showed that people tend to associate colors with preferences and meaning such as blues which are characterized as symbolizing things that are good for us, and others which are associated with bad things. Blue is often associated with blue skies and clear water, both of which are good for human health; whereas yellow-green tones are associated with toxins and poisons which are detrimental to the body.
One expert at the University of Illinois still maintains that the majority of scientists believe that red is the constant color, unchanging between humans in hue perception. But the question remains, why is red the only indifferent color?
Contributing Author: Caitlynn Gillyard