colour is a visual perceptual property that corresponds in humans as either red, yellow, blue or others. colour came from the spectrum of light which is the distribution of wavelength versus light energy. This spectrum of light interacts in the eye with light receptorsТ spectral sensitivities.
You can define colours numerically according to their coordinates. Furthermore, the physical specifications and categories of colours are associated with materials, objects, light sources and many more based on various physical properties like reflection, light absorption and emission spectra.
In was in 1666 when Sir Isaac Newton started experimenting with colours and their origin. For his experiment, Newton focused on the nature of colour spectrum found in the rainbow. His experiments with a glass prism led him to name the colours of red, yellow, orange, blue, green, violet and indigo. Complementary colours were discovered in his succeeding experiments. In these experiments, he came to the conclusions that colour is contained in the light and that white light is a combination of all colours in the spectrum.
Chromatics, which is the science of colour, involves the human eye and human brainТs perception of colour, its origin in materials, the electromagnetic radiation physics and the art colour theory. The physics of colour involves electromagnetic radiation which is defined by its intensity and frequency or wavelength.
Have you ever wondered why your eyes have the ability to distinguish colours? This is because of the sensitivity of various cells in your retina to the light of dissimilar wavelengths. Your retina has three cones or colour receptor cells. One cone is responsive to the light that you perceive as violet. The other two cones are related chemically and genetically, with one cone sensitive to light that you have known to be yellowish-green while the other cone perceives a light to be green.
- colour Blindness Ц Some people who are missing a colour-sensing cone are less responsive to the incoming light compared with those who have complete colour-sensing cones. People who are less responsive to the incoming light can distinguish only few colours, a disorder known to be as colour blind or colour deficient.
- Tetrachromacy Ц typically, humans are trichromatic which means they have three colour receptor cells. Meanwhile, many animals are tetrachromats which means they have four types of cones. Some tetrachromatic animals are birds, reptiles and spiders.
In a nutshell, colours are a function of biology and light, meaning no two people can see exactly the same colour. The thing to remember is, colour is not an exact science, thus the goal of every person is to use it in the best way possible for their specific application.