Colour theory

Colour theory covers underlying theoretical topics seen in visual art. It is a ‘catch-all’ term referring to the idea of complementary colours, depicting mood with colour, and various other ideas and practices used by artists, interior designers, game designers, and filmmakers.

The Colour Wheel

A basic colour wheel

The colour wheel is a simple representation of the different relationships between colours.

Primary Colours

The primary colours are red, blue, and yellow. This set of primary colours is based on pigments as opposed to light (which results in RGB - with red, green, and blue being the primary colours) and is a subtractive colour method -- mixing all the primary colours give black.

Secondary Colours

The secondary colours are colours created by mixing two primary colours: orange from red and yellow, green from blue and yellow, and purple from red and blue. The secondary colour being mixed is dependant on the mixing ratio between the two primary colours.

Basic Colour Harmonies

Complementary colours are found on opposite sides of the colour wheel, e.g. red/green, yellow/purple. ‘Complementary’ refers to the combination of elements “in such a way as to enhance or emphasize the qualities of each other or another”.

Analogous colours are a section of adjacent colours on the colour wheel, e.g. red/orange/yellow.

Triadic colours are a selection of three colours evenly spaced on the colour wheel, e.g. green/purple/orange.

Other harmonies can be found on this page.

Colour Definitions

Here are definitions for other words and concepts relating to colour theory.

Warm and Cool

'Warm' and 'cool' are relative terms describing temperature in a set of colours. Generally, 'warm' colours fall between red and yellow while 'cool' colours fall between blue and red. Green, as a secondary colour, can be made 'cooler' by mixing more blue than yellow and 'warmer' by mixing more yellow than blue.

The concepts of 'warm' and 'cool' are relative depending on palette: the reference point for warmness is red and for coolness is blue.

Hue, Saturation, Brightness

A visual explanation of Hue, Saturation, and Brightness

'Hue', 'saturation', and 'brightness' refer to various technical properties of a colour.

• Hue refers to the specific colour: red, blue, yellow, etc.
• Saturation refers to the vividness of a colour, or how much grey is mixed with a hue. It is measured in %; 0% saturation is pure grey while 100% saturation is the pure hue.
• Brightness refers to how much white/black is mixed with a hue. It is measured in %; 0% brightness is pure black while 100% brightness is pure white.

Colour Combinations

Here are example combinations of common colours and what effect it gives.

Red	Green is red's direct complement. The green/red colour scheme is often associated with Christmas. Using blue creates a neutral-temperature palette with red, as blue is cool complementing the heat of red. Combining with orange creates a warm palette while combining with purple creates a cooler palette.
Blue	Orange is blue's direct complement. The analogous blue/green combination creates a cool or 'fresh' palette, and has connotations with nature/the sea.
Green	Red is green's direct complement. Using green with brown creates an "organic" palette.

External Resources

1. How I See Color by PurpleKecleon (Flash)