Colour Theory and Practice: Mixing, Harmonies, Contrasts, Psychology
This domain asks you to predict what a mixture will do and to explain why a colour scheme works. Answers score when they name the system (additive or subtractive), the mixture logic and the perceptual effect.
Two systems, two sets of primaries
- Subtractive (pigment, ink): primaries cyan, magenta, yellow; secondaries blue-violet, green, red-orange. The traditional artist triad red-blue-yellow is an approximation of this model.
- Additive (light, screens): primaries red, green, blue; secondaries cyan, magenta, yellow.
- Mixing two primaries gives a secondary; adding the third, or the complement, neutralises toward grey or brown. Tint = with white, shade = with black, tone = with grey or complement.
Harmonies and contrasts
- Harmonies: monochrome, analogous, complementary, split-complementary, triadic, tetradic.
- Contrasts after Chevreul and Itten: simultaneous contrast, successive contrast, warm-cool, light-dark, saturation, quantity (proportion), complementary.
- Albers' principle: a colour has no fixed appearance; it shifts with its surroundings, so test swatches in context.
Psychology of colour
- Warm hues advance and energise, cool hues recede and calm; red reads as urgency, blue as trust, green as growth. These are cultural conventions, so phrase them as associations, not laws.
Worked example
Neutralise a bright phthalo green and build a muted scheme. Add a touch of its complement, alizarin crimson, in small increments: the green loses saturation and turns olive; add white and it becomes a sage tint, add grey for a deeper tone. Reasoning: complements cancel because together they contain all three primaries, and proportion matters, since a little complement shifts a lot.
Marks-losing traps
- Mixing three primaries plus white, producing chalky mud instead of a controlled neutral.
- Confusing additive complements (red-cyan) with subtractive ones (red-green).
- Using black to darken, which kills chroma; use the complement or a deep transparent pigment.
- Judging colour under warm artificial light instead of neutral daylight.
- Listing harmonies without explaining the relationship between the chosen hues.