The human eye and brain together translate light into color. Light receptors within the eye transmit messages to the brain, which produces the familiar sensations of color. Newton observed that color is not inherent in objects. Rather, the surface of an object reflects some colors and absorbs all the others. We perceive only the reflected colors. Thus, red is not in an apple. The surface of the apple is reflecting the wavelengths we see as red and absorbing all the rest. An object appears white when it reflects all wavelengths and black when it absorbs them all. Red, green and blue are the additive primary colors of the color spectrum. Combining balanced amounts of red, green and blue lights also produces pure white. By varying the amount of red, green and blue light, all of the colors in the visible spectrum can be produced. Considered to be part of the brain itself, the retina is covered by millions of light-sensitive cells, some shaped like rods and some like cones. These receptors process the light into nerve impulses and pass them along to the cortex of the brain via the optic nerve. Have you ever wondered why your peripheral vision is less sharp and colorful than your front-on vision? It\’s because of the rods and cones. Rods are most highly concentrated around the edge of the retina. There are over 120 million of them in each eye. Rods transmit mostly black and white information to the brain.
As rods are more sensitive to dim light than cones, you lose most color vision in dusky light and your peripheral vision is less colorful. It is the rods that help your eyes adjust when you enter a darkened room. Cones are concentrated in the middle of the retina, with fewer on the periphery. Six million cones in each eye transmit the higher levels of light intensity that create the sensation of color and visual sharpness. There are three types of cone-shaped cells, each sensitive to the long, medium or short wavelengths of light. These cells, working in combination with connecting nerve cells, give the brain enough information to interpret and name colors. The human eye can perceive more variations in warmer colors than cooler ones. This is because almost 2/3 of the cones process the longer light wavelengths (reds, oranges and yellows). About 8% of men and 1% of women have some form of color impairment. Most people with color deficiencies aren\’t aware that the colors they perceive as identical appear different to other people. Most still perceive color, but certain colors are transmitted to the brain differently. The most common impairment is red and green dichromatism which causes red and green to appear indistinguishable. Other impairments affect other color pairs. People with total color blindness are very rare. Birds, fish and many other mammals perceive the full spectrum.
Some insects, especially bees, can see ultraviolet colors invisible to the human eye. In fact, color camouflage, one of nature\’s favorite survival mechanisms, depends on the ability of the predator to distinguish colors. The predator is expected to be fooled by the color matching of the prey. Until recently, it was thought that dogs didn\’t see any color at all. Recent studies now show, however, that dogs can differentiate between red and blue and can even pick out subtle differences in shades of blue and violet. Previous: Next:
What is it? Pink and white or grey and mint green (Picture: Nicole Coulthard) It looks like the internet is baffled again by the simplest of things в a shoe. This, of course, is not the first time people have been debating the colour of a clothing item as last year we were all wrapped up in the white/gold or blue/black dress debacle and now we have the shoe. Is it pink and white or grey and mint green? Who knows? Well, the person who originally posted the photo of the shoe assures us that the physical shoes are actually pink and white but hundreds of people have been saying on social media that they can see the shoes as grey and mint green. It was the dress that captured the attention of the masses last year with many people saying theyВ see it as white and gold and others saying it is blue and black, however, the original poster showed other pictures in which the dress is definitely blue and black.
But what is the actual reason for the difference in perception of these colours? It is down to a variety of factors such as lighting, phone/computer screen display, brains interpretation and type of sight. There is no reason for absolute sure, but some photographersВ have come out to say that itвs all down to white balance. What is white balance? White balance is a feature that many photo editors and photographers will be familiar with and it refers to the actionВ of removing colour casts from aВ photo so that an object that is physicallyВ white, appears white in the photo. The reason a colour may look differentВ in a photograph than it is in real life is down to the colour temperature in the environment when you were taking the picture. If a colour temperature is вcoolв it means there will be more blue tones in the photo, if the colour temperature is вwarmв there will be more yellow tones in the photo. The dress may have appeared blue with the colour cast, but after white balance it can appear white. If this doesnвt convince you then there are several other theories that may explain the reason some of us see differentВ colours. One idea is that the screen of your phone or computer with whichВ youВ viewed the picture has manipulated the colour somehow. This is a fairly believable theory as most screens have a combination of colours that make up their display and they all have the colours in different proportions to give their customers what they think is the best display.
Although this would be a convenient explanation and could account for small discrepanciesВ in the colour identification, it is certainly not enough to account for the major difference between pink and green or black and gold. You could say it is down to peopleвs eyes, seeing as we all have varyingВ ratios of red to green cones in our eyes which cause everyone to perceiveВ colour in their own way, but usually in very subtle differences. More: This is particularly evident under bad lighting, like when you look at the stars and some people say they are red while others think they are pink. Again these discrepanciesВ would not be enough to account for the huge difference in colour perception of these pictures. One of the most plausible theories is that the colour perception discrepancies are down to colour constancy which is an ability that ensures that the perceived colour of an object stays constant despite changes in lighting. The shoe and the dress are both photographed up close and we have no idea about the environment or lighting and the brain interprets the colours based on what light might be falling on it. In short, we donвt know for certain, so let the debate rage! MORE: MORE: