Some information about colors:

Colour also spelled COLOR, defined generally, the aspect of any object that may be described in terms of hue, lightness and saturation. Color is a personal, mental experience. This received as reflected transmitted of radiated light from an object to our eyes. Hence, to realize colors, we need two essential things, viz., light and an object. Light is that form of radiation to which our eye is sensitive. It is a very narrow region in the wide region of the electromagnetic spectrum. White light is made up of a spectrum of seven groups viz., Violet, Indigo blue, Green, Yellow, Orange and Red (VIBGYOR). The colors of the spectrum are the basic building blocks of a much wider range, types of colors.

In physics, colour is associated specifically with electromagnetic radiation of a certain range of wavelengths visible to the human eye. Radiation of such wavelengths comprises that portion of the electromagnetic spectrum known as the visible spectrum – i.e., light.

Object can reflect light of transmit the light incident on them. Colors can be combined to produce other colors. When one color is added to another color, the combination color is called Additive Color. When one or more color is removed from white the colors that re not absorbed produce what is known as a Subtractive Color.

Color Models:

The human eye perceives color according to the wavelength of the light that reaches it. Light that contains the full color spectrum appears as pure white light. In the absence of light, the eye perceives black.

The properties of color can be mathematically defined using one of several color models. Three of the most common models are:

Hue, Saturation and Brightness (HSB)

The HSB model is based on the human perception of color. In the HSB model, all colors are described in terms of three fundamental characteristics:

Hue is the wavelength of light reflected from or transmitted through an object. More commonly, hue is identified by the name of the color, such as red, orange of green. Hue is measured as a location on the standard color wheel and expressed as a specific angle between 0 degree and 360 degree .

Saturation, sometimes called Chroma, is the strength of purity of the color. Saturation represents the amount of gray in relation to the hue and is measured as a percentage from 0 percent (grey) to 100 percent (fully saturated).

Brightness is the relative lightness of darkness of the color and is usually measured as a percentage from 0 percent (black) to 100 percent (white).

Red, Green and Blue (RGB)

Mixing three basic components of colored light in various proportions can represented a large percentage of the visible spectrum. These components are known as the primary colors: Red, Green and Blue (RGB). When the three primary colors overlap, they create the secondary colors Cyan Magenta and Yellow.

Since the primary colors combine to create white, they also called additive colors. Adding all the colors together create white that is all the light is reflected back to the eye. Additive colors are used to lighting video, film recorders and monitors.

Cyan, Magenta, Yellow and Black (CMYK)

While the RGB model depends on a light source to create color the CMYK model is based on the absorbing quality of ink printed on paper. As white light strikes translucent inks, a portion of the spectrum is absorbed. Color that is not absorbed is reflected back to your eye.

In theory, pure cyan, magenta and yellow pigments should combine to absorb all color and produce black, for this reason they are also called subtractive colors. Because all printing inks contain some impurities, these three inks actually produce a muddy brown and must be combined with black ink to produce a true black.

The primary and secondary colors are complementary colors. Two subtractive colors create a primary color; two primary colors create a subtractive color.

The CMYK model is used in four-color process printing. In this process, combining four inks reproduces color: Cyan (C), Magenta (M), Yellow (Y) and Black (K). The letter K is used to avoid confusion, because B might also stand for Blue.

Color Attributes:

· Age
· Appearance
· Associations
· Fashion
· Impulse
· Markets
· Moods
· Personality
· Preferences
· Presentation
· Products
· Recognition
· Reflectance
· Regional
· Seasons
· Sex
· Shape
· Stability
· Taste
· Tradition
· Visibility
· Warmth