Colour Theory and Application
What this domain tests
Colour questions check whether you can mix deliberately, choose a scheme, and use colour to describe light, form and distance.
Core rules
- Know the wheel. Pigment primaries are red, yellow and blue; mixing two gives secondaries (orange, green, violet); a primary plus its neighbour gives a tertiary. Complementary pairs sit opposite and neutralize each other.
- Separate the three properties. Hue is the colour name, value is light to dark, saturation is strength. A tint adds white, a shade adds black or a dark complement, a tone adds grey.
- Never darken with black. Shadows are darker and cooler: use a touch of complement or a cool dark. A red pot's shadow is a deep maroon, not red plus black.
- Choose a scheme - analogous, complementary, split complementary or triadic - and let one colour dominate. Warm colours advance, cool colours recede.
- Use simultaneous contrast: a colour looks lighter against dark and duller against bright.
Worked example
Shading a red earthen pot lit by warm sunlight. The lit face is cadmium red lightened with a little yellow; the terminator is crimson plus a trace of its complement (green) to neutralize it; the reflected light picks up a warm bounce from the ground; the cast shadow is cool violet-grey. No black anywhere, and the highlight is left as pale paper.
Traps that cost marks
Black mixed into every shadow; muddy greys from stirring three colours together; equal areas of complementary colours fighting; the same green for foliage near and far; over-saturated backgrounds that swallow the subject; and a scheme abandoned halfway through the picture.