The Color Theory

Colors are great. They create mystifying visuals. However, asynchronous usage of colors is chaotic and an eyesore. Hence understanding of how colors work in your favor is important for a good design. Color theory is a guide to color mixing and the visual effects of specific combination. It covers multitude of definitions, concepts and design applications. The color theory can be summed up in 3 logical and useful categories viz. The Color Wheel, Color Harmony and The context of how colors are used.

The Color Wheel

A Color Wheel or color circle is an abstract illustrative organization of color hues around a circle that shows relationships between primary colors, secondary colors, complementary colors, etc. Artists typically use red, yellow, and blue primaries (RYB color model) arranged at three equally spaced points around their color wheel. The arrangement of colors around the color circle is often considered to be in correspondence with the wavelengths of light, as opposed to hues, in accord with the original color circle of Isaac Newton. Scientists and artists have studied and designed numerous variations of this concept. Color scientists and psychologists often use the additive primaries, red, green and blue; and often refer to their arrangement around a circle as a color circle as opposed to a color wheel.

We begin with a 3-part color wheel.

Primary Colors : Red, yellow and blue
In traditional color theory (used in paint and pigments),

Secondary Colors: Green, orange and purple
These are the colors formed by mixing the primary colors.

Tertiary Colors: Yellow-orange, red-orange, red-purple, blue-purple, blue-green & yellow-green
These are the colors formed by mixing a primary and a secondary color. That's why the hue is a two word name, such as blue-green, red-violet, and yellow-orange

Color Harmony

Harmony is defined as characteristic which is achieved when the arrangement of all the parts makes up a pleasing effect; this could be seen in the chirping of the birds, breaking of waves and even n ice cream sundae.

In visual experiences, Colors add value to what the viewer see. They engage the viewer. Harmonious use of colors could help create inner peace. When something is not harmonious, it's either boring or is loud. Either way, the viewer looses interest. At one extreme is a visual experience that is so bland that the viewer is not engaged. The human brain will reject under-stimulating information. At the other extreme is a visual experience that is so overdone, so chaotic that the viewer can't stand to look at it. The human brain rejects what it cannot organize, what it cannot understand. The visual task requires that we present a logical structure. Color harmony delivers visual interest and a sense of order.

In summary, extreme unity leads to under-stimulation, extreme complexity leads to over-stimulation. Harmony is a dynamic equilibrium.

Some Formulas for Color Harmony

There are many theories for harmony. The following illustrations and descriptions present some basic formulas.

1. A color scheme based on analogous colors.
   Analogous colors are any three colors which are side by side on a 12 part color wheel, such as yellow-green, yellow, and yellow-orange. Usually one of the three colors predominates.
   
2. A color scheme based on complementary colors
   Complementary colors are any two colors which are directly opposite each other, such as red and green and red-purple and yellow-green. In the illustration above, there are several variations of yellow-green in the leaves and several variations of red-purple in the orchid. These opposing colors create maximum contrast and maximum stability.
   
3. A color scheme based on nature
   Nature provides a perfect departure point for color harmony. In the illustration above, red yellow and green create a harmonious design, regardless of whether this combination fits into a technical formula for color harmony.
   

Color Context

How color behaves in relation to other colors and shapes is a complex area of color theory. Compare the contrast effects of different color backgrounds for the same red square.

Red appears more brilliant against a black background and somewhat duller against the white background. In contrast with orange, the red appears lifeless; in contrast with blue-green, it exhibits brilliance. Notice that the red square appears larger on black than on other background colors.

Different readings of the same color

If your computer has sufficient color stability and gamma you will see that the small purple rectangle on the left appears to have a red-purple tinge when compared to the small purple rectangle on the right. They are both the same color as seen in the illustration below. This demonstrates how three colors can be perceived as four colors.

Observing the effects colors have on each other is the starting point for understanding the relativity of color. The relationship of values, saturations and the warmth or coolness of respective hues can cause noticeable differences in our perception of color.