Basic Colour Theory
Color theory encompasses a multitude of definitions, concepts and design applications - enough to fill several encyclopedias. However, there are three basic categories of color theory that are logical and useful : The color wheel, color harmony, and the context of how colors are used.
Color theories create a logical structure for color. For example, if we have an assortment of fruits and vegetables, we can organize them by color and place them on a circle that shows the colors in relation to each other.
Primary Colors: Red, yellow and blue
In traditional color theory (used in paint and pigments), primary colors are the 3 pigment colors that can not be mixed or formed by any combination of other colors. All other colors are derived from these 3 hues.
In traditional color theory (used in paint and pigments), primary colors are the 3 pigment colors that can not be mixed or formed by any combination of other colors. All other colors are derived from these 3 hues.
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.
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.
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.
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.
Colour Systems
There are two primary colour systems - methods by which colour is reproduced: additive and subtractive (also known as reflective). We use both on a daily basis - the screen you're reading this article on uses additive colour to generate all the colours you see, while the book you're reading uses subtractive colour for its front cover.
In simple terms - anything that emits light (such as the sun, a screen, a projector, etc) uses additive, while everything else (which instead reflects light) uses subtractive colour.
Additive
Additive colour works with anything that emits or radiates light. The mixture of different wavelengths of light creates different colours, and the more light you add, the brighter and lighter the colour becomes.
Subtractive
Subtractive colour works on the basis of reflected light. Rather than pushing more light out, the way a particular pigment reflects different wavelengths of light determines its apparent colour to the human eye.
