Colour Theory and Colour Systems
This domain tests colour vocabulary, the difference between additive and subtractive mixing, standard harmony schemes and the logic of colour-order systems. Expect definitions, palette justification and correction of common colour-wheel errors.
Core rules
- Additive mixing uses light: red, green and blue primaries; all three make white. Subtractive mixing uses pigment or print: cyan, magenta and yellow; all three approach black. The traditional artist’s wheel uses red, yellow and blue, with secondaries orange, green and violet.
- Hue is the family name; value is lightness; chroma/saturation is purity. A tint adds white, a shade adds black, a tone adds grey or a complement.
- Munsell arranges colour in three dimensions (hue, value, chroma) and writes notation such as 5R 4/14. Ostwald uses a hue circle and a solid built from white and black content.
- Harmonies: monochromatic (one hue), analogous (neighbours), complementary (opposite), split-complementary (opposite plus its two neighbours), triadic (three evenly spaced) and tetradic (two complementary pairs).
- Simultaneous contrast: a colour shifts according to its surround. Successive contrast: a staring afterimage appears in the complementary hue.
- Warm hues advance; cool hues recede; this affects hierarchy and spatial depth.
Worked example
A clinic needs a calm but visible palette. Choose a blue-green base, a neutral grey-white and a warm ochre accent. The base and neutral are analogous/neutral; ochre is roughly split-complementary to blue-green, so it stands out without vibrating. Keep signage text at high value contrast (dark on light) rather than relying on hue alone, because red–green confusion is common. Harmony controls mood, complement controls emphasis, and value controls legibility.
Traps that cost marks
- Calling green a primary on the pigment wheel, or mixing RGB and RYB terminology.
- Using “tint” for any lighter colour and “tone” for any darker one.
- Naming a harmony without checking the angle on the wheel.
- Assuming a screen colour will match printed ink; gamuts differ.