There is a theory that states that humans' ability to see is very limited, so that we can't see all colors. This invisible color is called the 'impossible colour'.
Color is a limited range of light that is only along the electromagnetic spectrum that humans can see. In other words, color is the brain's way of using our eyes, interpreting the various frequencies in wave motion. With the hypothesis that we can only interpret light within a limited range, the next question arises: does that mean there are colors we can't see?
To process color, we need to know the function of the retina which consists of light-sensitive cells called rods and cones. They transmit information to nerve cells in the inner retina. The rods are responsible for our perception of light and dark and our peripheral vision. The cones, found in the center of the retina, allow us to see color. These fall into three types, each sensitive to a different range of light waves.
Humans have more cones that are sensitive to red light than any other type, meaning human vision is best for lighter colors like red, orange, and yellow.
Is it possible to see impossible colors?
Process-opposite theory of color perception has been around since the 1970s. This theory basically states that it is impossible for any human being to see colors like bluish yellow and greenish red. However, in the 1980s, two researchers conducted an experiment to see if it was possible to 'trick' the brain into seeing these colors.
Their experiment involved subjects staring at an image consisting of two red and green stripes. To ensure the subject's eyes stay fixed on the opposite color, their head is stabilized with a chin rest and eye movements are tracked using a camera -- it's not recommended to do this experiment yourself at home.
The experimental results were surprising. Under the right conditions and for the right amount of time, the boundary between the opposite colors seems to gradually disappear, and the so-called forbidden color or impossible color manages to appear. However, further experiments on this matter are still needed to find out more about how well the human eye can perceive color, the London Vision Clinic reported.