The Modern Theory of Color

The color of a material depends not only upon itself but also on the eye of the observer and on the light. When two persons observe an object they cannot see the exactly same color though they explained it as a same named color. The matter can be expended to color blindness where the difference between the colors specially red and green is not compared by the observer. The light we consider is a sunlight which is composed of all colors.

The light is divided into its constituents if it can be allowed to fall on a prism. Again we know that when light falls on a body some of the lights are reflected, some absorbed and some transmitted. As a result when light falls on a body if it reflects all the colors then we see white color, if all colors are absorbed we see black color. So Color is the result of an interaction between a chromophore group or color bearing object and light within the visual range. To produce color a certain weavelength of reflected light strikes on the retina of eye. The weavelength of the light must be within the visible region from 4000A⁰ to 7000A⁰.

Below 4000A⁰	4000	4500	5000	5500	6000	7000	Above 7000 A⁰
UV	Violet	Blue	Green	Yellow	Orange	Red	Infrared
Invisible	Visible						Invisible

Here, range of white color is from 4000A⁰ to 7000 A⁰. Light of only one color is absorbed in which case the object will appear to have the complementary color. Thus, if the light is absorbed from the violet region of spectrum, the substance will be seen as yellow. If light is absorbed from the green blue region, the substance will appear orange.

Without these some definition have to keep in mind such as Hue, Value, Chroma. Hue is the color of an object i.e. red, black etc that appears. Value is the brightness of color or the degree of lightness and darkness. Chroma is the strength of color which represents its vividness or dullness.