We see our world in a huge variety of colour. However, there are other “colours” that our eyes can't see, beyond red and violet, they are: infrared and ultraviolet.
Red-green and yellow-blue are the so-called "forbidden colors." Composed of pairs of hues whose light frequencies automatically cancel each other out in the human eye, they're supposed to be impossible to see simultaneously. The limitation results from the way we perceive color in the first place.
Magenta: The colour that doesn't exist - BBC Reel.
There are three main types of “impossible” colors: Forbidden colors. These are colors our eyes simply cannot process because of the antagonistic way our cones work, for instance “red-green” or “yellow-blue.”
Purple, magenta, and hot pink, as we know, don't occur in the rainbow from a prism because they can only be made as a combination of red and blue light. And those are on opposite sides of the rainbow, nowhere near overlapping. So there is no purple or hot pink in the rainbow from a prism.
The colours of the rainbow are Red, Orange, Yellow, Green, Blue, Indigo and Violet.
The hardest color to see in a rainbow is indigo. Since indigo falls between blue and violet, it's really hard to distinguish this darker blue.
First and foremost, it is critical to recognize that the color magenta is merely an illusion created by our eyes. This color, a mix of purple, red, and crimson, is very unique in that it does not appear in the visible spectrum of light and lacks a length of illumination that corresponds to that specific color.
Blue is a tough color to spot in nature because there is no naturally occurring blue compound to color things blue.
Chimerical Colors
The impossible colors reddish green and yellowish blue are imaginary colors that do not occur in the light spectrum. Another type of imaginary color is a chimerical color. A chimerical color is seen by looking at a color until the cone cells are fatigued and then looking at a different color.
Today researchers use physics to invent new colours, inspired perhaps by the iridescent shades created by structures in butterfly wings that scatter light. These new structural colours are the result of an interaction between light and nanoscale features many times thinner than human hair.
For tens of thousands of years, humans have created colours through simple chemistry. At first we used dyes found in nature such as berries and charcoal. Later, new pigments were synthesised in the lab.
Researchers estimate that most humans can see around one million different colors. This is because a healthy human eye has three types of cone cells, each of which can register about 100 different color shades, amounting to around a million combinations.
Although our visual system can paint a vibrant portrait of the world, its palette of colors is actually quite limited, as we only see between 390 to 750 nm of the full electromagnetic spectrum while the remaining trillion wavelengths escape our view.
Cone cells help detect colors. Most people have three kinds of cone cells. People without all three see fewer colors, sometimes called color blindness. Some cones respond more strongly to blue light.
Despite the extraordinary experience of color perception, all colors are mere illusions, in the sense that, although naive people normally think that objects appear colored because they are colored, this belief is mistaken. Neither objects nor lights are colored, but colors are the result of neural processes.
So, What Are the Hardest Colors To See? The short answer is Red. The red color is the hardest to see in the darkness.
It only exists in your head. Bevil Conway, a neuroscientist who studies color and vision at Wellesley College, explained it this way: “Color is this computation that our brains make that enables us to extract meaning from the world.”
Light consists of electromagnetic waves, and colour depends on the wavelength. If colours were simply a naming scheme for wavelengths then pink is not one, because it is made up of more than one wavelength (it's actually a mix of red and purple light).
Brown is a color. It can be considered a composite color, but it is mainly a darker shade of orange. In the CMYK color model used in printing and painting, brown is usually made by combining the colors orange and black.
Green, the mixture of blue and yellow, can be seen everywhere and in countless shades. In fact, the human eye sees green better than any color in the spectrum.
The most popular color in the world is blue. The second favorite colors are red and green, followed by orange, brown and purple. Yellow is the least favorite color, preferred by only five percent of people.
One of the rarest forms is multiple, or double, rainbows. They occur when several rainbows form in the same place at the same time. It takes at least one primary rainbow to generate this sight, as well as several other secondary rainbows. There is always space in between each one.