Color Theory

Color Basics

According to the definition in the worqx.com website, color is a perceptual characteristic of light. There are 3 major factors which are used in describing a color: its name, how pure it is and the value of its lightness. Hue is the value of the color (the color name), the purity of a hue is indicated by the value of saturation and the intensity value decides the brightness of a color.

A hue can has a number of variations which are created by mixing a pure hure with different colors. The 2 most important variation of a hue called shade: a variation produced by adding black color and tint: a variation produced by adding white color.

Major Color Systems

RGB Color System: this is an additive color system which is usually seen in computer screen. We call it as an additive color system because as more colors are added into it, it will produce a brighter result color. 3 primary colors of the RGB color system are Red, Green and Blue.

CMYK Color System: this system is called as a subtractive color system which is mostly used in printing. Although it only has 3 primary colors which are Cyan, Magenta and Yellow, the Black color is added into this system to produce a black color (practically, there is impossible to produce a pure black color by mixing cyan, magenta and yellow).

Besides these most popular ones, there are also have other color systems which are used in more specific situations such as the HSV color system.

The Color Wheel

Traditionally, the color wheel is a color circle including 3 colors which cannot be produced by mixing any others colors. They are Red, Blue and Yellow. So, the color wheel with only these 3 primary colors is called as a primary color wheel.

Primary Color Wheel

The Secondary Color Wheel contains primary colors and colors produced by mixing primary colors.

Secondary Color Wheel

And the Tertiary Color Wheel addes colors formed by mixing primary colors and secondary.

Tertiary Color Wheel

Based on the Color Wheel, there are some terms describing the combination of colors:

Analogous Colors: the combination of colors which are located closed together on the color wheel.

Complementary Colors: the combination of colors located opposite each other on the color wheel.

Monochromatic Colors: the combination of a pure hue and its variations.

References:
http://www.worqx.com/color/color_basics.htm
http://www.colormatters.com/colortheory.html
http://www.worqx.com/color/complements.htm