THE HUMAN COLOR PERCEPTION

A OVERVIEW HOW COLOR COMES INTO THE WORLD

The Human Color Perception

If you want to be a good make-up artist, you should know more about our color perception then normal basic trained people. If you go more deeper, we can give you a fundamental knowledge about color vision. This will make yourself a better make-up artist. 

The human eye can distinguish 10 million different color shades. But how can we do this and how is a color created. 

How can we see a object?

The first thing we need to know is that we perceive light with our eyes from outside of our body. Light is everywhere in space and surrounds us continuously. We need light rays to observe our world. Without a light source it is not possible to see anything. Everything would be black around us. We can percept an object by receiving light through the lens of our eye. The light rays enters the inner of our eyes and hits some special cells. This special light sensitive cells are the rods & cones and forms the retina. 



To be able to see an object, it is necessary to have a light source which emits light. This light rays are reflected from an object like a face and enter our eye. Only if an object is reflecting light, we can see the object. If you see different objects with different colors, it means that the object is absorbing some parts of the white light and reflect only a part of the original sun light. 


Why we see colors?

Many people would say, that they know exactly what a color is. But is this really true? Let´s have a look about the creation of colors and how we percept them. In general we all would say that color is light. This is only half true, because light is a electro magnetic ray, which is emitted by different light sources. Light is created always by matter, which has a specific temperature.  As higher the temperature, as more light frequencies a object is emitting. 

Almost all light sources emits more or less a full spectrum of different visible light rays which represent the white light. Of course the sunlight has a much bigger spectrum then a candle light, but this comes later in detail. Now we see a general light source like our sun. The bright white light of our sun is a mixture of many different wavelength. A light ray can have different frequencies with different wavelength. This is like a sound wave in the air. There are long waves and shorter waves of light. In our eye we have special nerve cells which are able to distinguish different wavelength. This light sensitive cells are the CONE´s. 


A white light has already all colors (ray frequencies) inside. This can be shown by separating a white light beam into single parts. This can be done by a prism or if you look into nature, by a nice rainbow you see in the sky. This are the building blocks of color vision. But only because you see colors, it does not mean that there are really colors in the outside world. Outside of our body, there are only different energy waves with different frequencies, which has no color by themselves. 

What is creating all colors

Our brain is the creator of the colors. All energy waves which we percept from the outside world are getting transformed into a color information by our brain. Without a observer with a brain, colors do not exist. Only with a conscious mind, we can distinguish colors. 

How are all the different colors created?

The human eye can distinguish over 10 million colors and shades. How is it possible to percept such a huge amount of different colors? For this huge task our eyes and brain has a simple method. In the retina we have special rod & cone cells which are able to percept a wide range of the light spectrum of the sun. The special nerve cells which are responsible for distinguish colors are the cone cells. 

Because our eye is not possible to differentiate all the waves separately the human vision has a perfect trick. We need only 3 cone cells to create all colors in our brain.

S-CONE

creates out of  380 - 540 nm light rays a blue color vision

M-CONE

creates out of  440 - 670 nm light rays a green color vision

L-CONE 

creates out of  500 - 690 nm light rays a red color vision

and is also responsible for the continuously color vision to close the color wheel


The visible light starts from 380 nm and ends at 780 nm wavelength. In between this range all color from the visible light range are located. Our cone cells in the retina can percept different ranges of the full spectrum. Our brain is creating colors in the way how much each cone cell is stimulated. In case only the S-CONE is active we see a blue color. If the M-CONE and the L-CONE is active, we see a yellow color. 


WAVELENGTH COLOR CONE
400 nm Violet S-CONE and L-CONE
450 nm Blue S-CONE
480 nm Cyan S-CONE and M-CONE
530 nm Green M-CONE
580 nm Yellow M-CONE and L-CONE
650 nm Red  L-CONE

The different color perception is based on the 3 different CONE´s in our retina. All colors are based on a mixture of the 3 stimulated CONE cells. 

3 CONES are enough

With the 3 color sensitive cells the brain can create all other colors from mixing this 3 colors together. One color represent one CONE cell. This mixing is an additive mix and works with colored light. For pigments we need to look deeper into some circumstances.



If you set the newly created colors, which are mixed out of two colors in between, then we get automatically the subtractive primary colors for print and mixing. This are YELLOW (2 CONES M+L), MAGENTA (L+S CONE) and CYAN (M+S CONE). 


This brings us naturally to our CONE color wheel. You find here more information about our CONE COLOR SYSTEM


Light Sources

First of all we need a light source to create light rays in a space. It is important to know why different light sources can affect your make-up work. Every light has a different spectrum. This means that not all light waves are inside the white light. We will learn more about a white point, because our brain is tricking us the whole day about what we think it is white. 

Sunlight

is the most important light source in our world. It has the most natural spectrum and creates a very nice and healthy spectrum.


Artificial Light

Tungsten light has a much more reddish color then the normal daylight. 

Candle Light

A candle light are not very hot and has a very yellow reddish spectrum. All objects can only reflect the light what the candle emits. The colors under such light is different then in daylight. 

A very important part of the light perception is the light source by itself. Because a object can only reflect or absorb the light from the environment. If the object is in the sunlight, it can fully reflect all kind of light rays, because the sunlight has a very wide spectrum of rays and our eyes and brain is conditioned to see this light as the most natural light. Not all light sources has the same amount of wavelength inside the spectrum. Every light source has it´s own light spectrum. This makes a light warmer or colder. In general colder light sources looks more reddish and hotter light sources tends to be white or blueish. We will see why this happens and why it is important to know this.