Colour theory: the basics

In short: Colour theory explains how colours arise, mix and work. A distinction is made between additive mixing (light) and subtractive mixing (pigments).

In more detail: Screens mix red, green and blue (RGB), printers cyan, magenta, yellow and black (CMYK).

In detail

• Primary colours: Depending on system red-yellow-blue (painting), RGB or CMY.
• Secondary colours: Mixed from two primaries: orange, green, violet.
• Colour wheel: Orders colours; complementary colours lie opposite and intensify each other.
• Properties: Hue, saturation and brightness.
• Warm and cool: Red and yellow appear warm, blue and green cool.
• Harmonies: Analogous (adjacent), complementary, triad.
• Effect: Colours trigger associations, culturally different.
• Contrast and legibility: Important for design (bildkomposition-goldener-schnitt).