Color psychology is the study of hues as a determinant of human behaviour. The basic idea is that the colors around us impact the way we live, the way we feel and the way we are. Designers and marketers understand the power of color, and you can learn it too. Since it is still a theory, everything should be taken with a grain of salt, and every person responds differently. Yet, there are general phenomena or rules to be followed. That is what we are about to explore in this series of articles.

Before we dive into the different aspects and categories, we have to get on the same page. We need to understand how the vision works, the physics of light (therefore color), and how our eyes transmit and understand the inputs as well as the history of the psychology of color. I have been studying visual perception and color psychology for quite some time, and it totally changed the way I look at the world. It is good to know that my growing up in Slovakia (Europe) also had an impact on how I feel and perceive color. If you live in a different part of the world, in a different culture or different circumstances, you might want to test everything. What doesn’t change is Science, and that’s where we are about to begin.


Perception is what we are aware of. In terms of vision, it is what we are actually aware of seeing when looking out in the world. It is obviously very subjective, and the only way we can know what a person is aware of seeing is by asking that person. So we have to distinguish how we can measure what we are aware of seeing and what the world really looks like. Psychophysical measurements refer to subjective visual perception, which can be measured only by comparative measurement and physical measurements to the actual reality of the world measured by tools like rulers, photometer, and many different gadgets we might explore later.


The next term is luminance. In other words, it refers to physical word for light intensity, aka lightness or darkness and here comes the tricky part. We actually don’t know exactly how our vision works, but we are closer every year. Just look at the first picture 1 and then scroll to picture 2. Those 2 grey dots are identical color, and we know that by measuring their wavelengths (spectrophotometer). As soon as they are exposed to different backgrounds, the perception of their lightness change, and it will change back immediately as you come back to picture 1.

You might think that this would not happen if it was color, right? I’m sorry to disappoint you, look at the picture with Rubik’s cube.

Some people have color deficiencies or are color blind, and for those people, this might look identical or totally different, but for those with normal color vision, it should do the trick.

There are many more visual illusions like skewed lines that look longer or shorter, spatial illusions regarding illusions in-depth or some harder ones like stereograms (these require a technique called the free focus). I will definitely make an article about optical illusions later.

Light and the Electromagnetic spectrum

This is an exciting part of visual perception and how we interpret stimuli that get into our eyes. Humans range of vision ranges from 400 nanometers to 700 nanometers, as displayed in the picture below. Only in this range we are able to see and therefore see the colors.

There are many more electromagnetic wavelengths to both sides of the spectrum; smaller to the left with higher frequencies and larger to the right with lower frequencies. It is very important to understand the term light is widely used only to the range of which humans can see, but there are all the other wavelengths in the world that we just can’t see but can measure(x-ray detectors, radars). So the light is really defined by human evolution.

Introduction to Color Psychology: How our vision works?

The Eye

The next part of the puzzle is the way an image is created in our eye. Let’s use an analogy of a camera. What you need to understand is that the images we see don’t exist in the real world. What exists in the world is a chaotic mess of photons running around and bouncing off surfaces in any directions. So once the photon hits the eye, it is transmitted to the retina the same as light is transmitted to the film in a camera. Of course, the image is upside down, but we don’t see the world upside down, right?

Introduction to Color Psychology: How our vision works?


Here comes to play an ingenious mechanism of an eye -> thalamus –> primary visual cortex combination that is responsible for what we see (there is one more thing called the inverse problem, so if you are interested, here is a link to that). Let’s look into that, so we have the whole picture of whats our vision about.

The Cornea is the first step into or understanding a vision. What it does is redirecting or refracting the light that’s flying around and pointing them in the right direction so it can form the image. You might think that is it the Lens that is doing that, but that’s not true.

A Lens‘ function is to make the light that goes into the eye (and through the Cornea) land precisely on the retina. Not in front and not behind.

The Ciliary muscles and Zonule Fibers are used to form the Lens into a shape that is best for landing the light exactly onto the retina.

And now let’s talk about the
Retina. Not the Apple display but the actual retina in our eyes. It’s the visual sensitive part of the eye consisting of rods and cones. These tiny parts are responsible for transmitting information to the brain. The two types, however, do slightly different things. Cones are most densely located in the retina’s Fovea area, while rods are primarily located in the peripheral regions. Cones functioning very good in very bright circumstances, so they are used mainly by your eye in sunlight, indoor light and scarcely in the moonlight. On the other hand, Rods are very good in dark, starlight and moonlight.

Have you ever heard that you can not see color in the dark? That you have basically black and white vision? This is true, but it’s not because rods are less sensitive to light stimuli. It is because they can not see color. And since they are made for use in the dark, you can not see the colors as cones would. You also see more broadly since rod are well distributed around the peripheral parts of the retina.

Fovea is the region that we use to see with the greatest detail, it’s the part that has the most excellent sensitivity to detail in light and has the finest resolution (again, cones distribution). To get the light to land on the fovea we have to align our eyes, that the light goes straight onto that point.

Introduction to Color Psychology: How our vision works?

The Primary Visual Pathway

All of the stimuli caught by the retina are then transferred via optic nerve further to the brain, where it is processed. As I mentioned before, understanding the image and vision is still very much unknown, but we can at least understand some of its processes.


We can use the image below. Not everything needs to be understood right now, but the main information is this. When you see an image, the stimuli from your eyes are transferred as right and left. They travel through optic chiasm, where they are separated. The right signal goes to the left hemisphere and the left part to the right. The answer to this process is not really clear. The best guess would be again evolution and the way our predecessors, mainly fish, have their eyes on both sides. What we learned is that it’s more efficient in fighting danger with a tail to have the signal from the left eye send to the right part of the brain. Therefore we might have inherited this setup. But again, it is just a theory.


Introduction to Color Psychology: How our vision works?


After the signal gets sorted out, it travels to the primary visual cortex, where the color is recognized. Many layers respond to different colors, and it’s all very interesting and complicated, so I’ll stop right here and let you decide if you want to get deeper into the mystery of our vision. (If yes, I recommend taking the course by clicking the link at the end of this article)


This is the end of the path of the light and the beginning of color psychology. The key takeaways are:


  1. The vision is a highly complex mechanism. It has many mysteries, and it can not always be trusted (as we have seen with the illusions).
  2. The process of image-making starts with light coming into the eye and end at the primary visual cortex, where it is interpreted to different colors.
  3. The visible light spectrum and, therefore color is ranging from 400nm to 700nm.
  4. We can only see color with cones and can not see color in the dark.

In the next part, we are going to explore the history of color, names of colors, and how our culture and circumstances shape our color perception.