Color Color Color (American English), or colour (Commonwealth English), is the characteristic of human visual perception described through color "categories", with names such as red, orange, yellow, green, blue, or purple. This perception of color derives from the stimulation of cone cells in the human eye by electromagnetic radiation in the visible spectrum. Color categories and physical specifications of color are associated with objects through the wavelength of the light that is reflected from them. This reflection is governed by the object's physical properties such as light absorption, emission spectra, etc. By defining a color space, colors can be identified numerically
Natural Color System lightness value "v" as the sample on the reference scale to which it has the least noticeable edge-to-edge difference. Two examples of NCS color notation—the yellow and blue shades of the Swedish flag: The NCS is represented in nineteen countries and is the reference norm for color designation in Sweden (since 1979), Norway (since 1984), Spain (since 1994) and South Africa (since 2004). It is also one of the standards used by the International Colour Authority, a leading publisher of color trend forecasts for the interior design and textile markets. In order to be able to manufacture physical representations of