Few years ago, in a weekend I was little upset as my daughter couldn’t recognize the colors that I have taught. It seems nothing to worry as she was just three years old. But it was not that simple for a father to accept, as she is normal and very keen in learning other things. This made me unrest for few weeks and I had a reasonable doubt, whether she could recognize the colors. This made me mad few days and I was seeking a way to identify. “Can she see the colors that I see ?” was the my first question. Secondly, “Does calling a color with the same name implies that we both see the same?”. What happens if she sees my Red as Blue, but still calling red, as I have taught her as red.
It made me to think in another way. As I call the color, as same as the color that you call, does not imply that both of us see the same color. It is easy to digest that the red that you see may be little different than the red that I see, but it’s hard to believe that the red that you see being blue for another. Ultimately, in day to day life no one cares about what you see, but all we call an object as the same color as we were taught to call as.
Let me explain how it works……
We all have sensors, called photoreceptors or color sensitive cone cells, back of our eyes, that turns light (electromagnetic waves) into electrical signal by facilitating to perceive colors by detecting the frequency of the electromagnetic wave. We have many different kinds of these cone cells, and most people have three different photoreceptors for coloured light, which are sensitive to blue, green and red respectively. These three types of photoreceptors allow us to perceive full range of colors. It is actually more accurate, if I say that these photoreceptors are sensitive for short (blue), medium (green) and long (red) wavelengths of visible light.
Source: https://goo.gl/images/3fKRU1
So that, what is sensed is wavelengths rather than colors. This allows someone to raise a reasonable question that, as our eye distinguish wavelengths (rather than colors), should it be interpreted by my brain as exactly same as your brain. We know only little about our brain, and there is no way for me to see what you really see. For an example let us select two individuals with healthy vision. So that they can recognize colors as any human expected to be. But I am not sure about a way to gurant the red of one is not blue of the other or completely something else that the other even cannot imagine.
Photoreceptors
There are people with weak or malfunctioning photoreceptors where they can’t see some colors (actually cannot differentiate some colors from another), which is known as color blindness. This is little common than you think, as 8% of men in the world suffer from color blindness (but only 0.5% of women are affected by the same). In this case, people see colors differently. It will not be triggered until the person understand that he/ she cannot differentiate two colors but someone else can.
On the other hand, some people have more powerful photoreceptors than a usual human. Scientist call these people as tetrachromats, which means “four colors”, as it is believed that they have photoreceptors, sensitive for four peak wavelengths, rather than three. In other words, these people can see color that most of us cannot see. I know, what runs in your mind “So what are the colors that they see, which I cannot?”. What really happens is, as their fourth type of receptors are sensitive for the wavelength which is still in the range of visible light (most of the time in between red and green), still they see the colors that you see. But they can differentiate one color from another, which is slightly different from the other, which you cannot. Logically yes, they see colors that you cannot see, as you cannot differentiate, you see both as same, but for them its two.
Let us assume if there is a person with the fourth type of photoreceptor sensitivity which lies around the range of X-ray (or infrared). So, he/she would be able to see your bone and skull through your body or the rays passing from your TV remote controller (like some birds and reptiles).
Emotional responses and colors
Colors affect our emotional responses, which is proved by many researches and it is a well known phenomenon. But how does it affect on human emotions? So that there is a reasonable question that, as individuals can see colors in a unique way, whether the colors affect the individual’s emotions in a unique way. In other words, do different colors make individual’s state of mind calm & quiet or irritation? It is true that there is a personal preference with regard to colors (as one prefer blue but another red). But the logic behind the effects of colors on emotions is little different, as actually you don’t see colors but perceive wavelength of the electromagnetic waves. So that differences in the way we each perceive colors, don’t change the emotional responses, that we have on them. Regardless of what you actually see when you look at a clear sky, it’s shorter wavelengths (which we call “blue”) that tend to make us calm, whereas longer wavelengths (yellow, orange and red) make us more alert.
Researches suggest an interesting fact that even one cannot differentiate colors (color blind) still expected to experience a calm and quiet state of mind when looking at the clear sky as the part of the brain which works on the emotions based on the perceived wavelength of the electromagnetic wave.
Summary
When we are born, our neurons are not configured to respond to color in a default way. Instead, each of us develop a unique perception of color. That particular color is very personal and subjective.
Further, it is very clear that no one can see the world as someone else. It is like, both agree with something as both of them call it in the same name, but they have no way to verify that what they see is identical. We use common words, and use them to refer shared experiences, but nobody can see the same sunset, as perception is a property of the person rather than the sunset.