The human eye and brain together translate light into color. Light receptors within the eye transmit messages to the brain, which produces the familiar sensations of color.
Light travels into the eye to the retina, located on the back of the eye. The retina is covered with millions of light receptive cells called rods and cones. When these cells detect light, they send signals to the brain. Most people have three kinds of cone cells, and every color stimulates more than one cone. Their combined response produces a unique signal for each color, and millions of different colors can be distinguished this way. These cells, working in combination with connecting nerve cells, give the brain enough information to interpret and name colors.
Newton observed that color is not inherent in objects. Rather, the surface of an object reflects some colors and absorbs all the others. We perceive only the reflected colors.
Thus, red is not “in” an apple. The surface of the apple is reflecting the wavelengths we see as red and absorbing all the rest.
An object appears white when it reflects all wavelengths and black when it absorbs them all.
Red, green and blue are the additive primary colors of the color spectrum. Combining balanced amounts of red, green and blue lights also produces pure white. By varying the amount of red, green and blue light, all of the colors in the visible spectrum can be produced.
The colour Red has the longest wavelength and Violet has the shortest wavelength in the visible spectrum.
VIBGYOR – is the name given to the colours of the rainbow and they are in ascending order of their wavelength they are as follows,
Violet < Indigo < Blue < Green < Yellow < Orange < Red.
Light travels into the eye to the retina, located on the back of the eye. The retina is covered with millions of light receptive cells called rods and cones. When these cells detect light, they send signals to the brain. Most people have three kinds of cone cells, and every color stimulates more than one cone. Their combined response produces a unique signal for each color, and millions of different colors can be distinguished this way. These cells, working in combination with connecting nerve cells, give the brain enough information to interpret and name colors.
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. Of course, this will vary for people who have a color impairment (or are ‘colorblind’).