Painting: colour theory and medium handling
Painting: colour theory and medium handling
This domain tests pigment mixing, colour relationships and control of the painting medium. The examiner looks for clean colour, deliberate value changes and a surface that is not muddy or overworked.
Core rules
- Traditional pigment primaries are red, yellow and blue; secondary colours are orange, green and violet. Complementary pairs (red–green, blue–orange, yellow–violet) neutralize each other when mixed. A tint is made with white, a shade with black, and a tone with grey or a complement.
- Warm colours (reds, oranges, yellows) advance; cool colours (blues, greens, violets) recede. Use this to create depth, not as a fixed rule for every picture.
- For poster colour, keep the paint opaque and load the brush moderately; for watercolour, control the water and work from light to dark because transparent washes cannot be lightened later. Let layers dry before glazing to avoid lifting the underpainting.
- Clean the brush between colours and change water often. Test a mixed colour on a scrap of the same paper before applying it to the painting.
Worked example
To mix a muted olive green, start with yellow and add small amounts of blue until the green is correct, then add a tiny touch of red (the complement of green). Reason: the red neutralizes some of the green's intensity without turning it grey-black; adding black would deaden it and reduce its chromatic strength.
Traps
Overmixing complementary colours produces mud. Adding black to lighten a colour is wrong; use white for a tint. Too much water causes blooms and bleeding in watercolour, while too little water makes poster colour streaky. A dirty brush contaminates every subsequent mix.