The Color Wheel
The color circle can be divided into warm and cool colors. Warm colors are vivid and energetic, and tend to advance in space. Warm colors are hues from red through yellow, browns and tans included; cool colors are often said to be the hues from blue green through blue violet, most grays included. Cool colors give an impression of calm, and create a soothing impression. White, black and gray are considered to be neutral.
Color HarmoniesColor harmonies consist of two or more colors with a fixed relation in the color wheel. The color scheme used in a design is important to communicate an idea effectively to the audience using a visual design. Colors can be used to set a specific mood, attract the attention of the viewer or to make an emphasis on a particular information. Colors can bring warmth or coldness, excitement or tranquility, elegance or luxury to each design. Selection of right colors and color combinations is important to present a design as best as possible. It can be concluded that the color is the most powerful design element if we use it effectively. The different basic techniques widely used to define color schemes based on the color wheel are illustrated below.
Note that the hues vary drastically in the two color models. In RGB color wheel the colors are red and cyan while in RYB it is red and green.