Colour is the visual perception based on the electromagnetic spectrum. Is the visual perceptual property corresponding in humans to the categories called red, yellow, blue, green, etc. Because the perception of color is an important aspect of human life, different colors have been associated with emotions, activity, and nationality.The familiar colors of the rainbow in the spectrum, include all those colors that can be produced by visible light of a single wavelength only. A study says that the eye can see one thousand shades of light, as well as one hundred levels of red-green and one hundred levels of yellow-blue.Ten million shades of color! However, they all stem from 11 main colors red, orange, yellow, green, blue, purple, pink, brown, gray, black and white. The rest are just combinations of these colors.