Colour Theory and Painting
Colour Theory and Painting tests whether you can mix the colour you actually see, not the colour you assume, and whether you can control paint as a material. Marks come from accurate value, believable colour relationships, clean mixing and deliberate handling.
Describe colour in three dimensions
Munsell's hue, value and chroma give you a working vocabulary. Match value first (squint and the hues vanish, leaving a grey scale), then hue family, then chroma. Most student errors are value errors disguised as colour errors.
Mixing logic
Choose a pigment family, adjust value, then kill chroma with a touch of complement rather than black. Black plus white gives a dead grey that reads as dirt next to real shadow colour; a shadow on white plaster is usually a cool blue-violet or greenish grey with reflected light from the surroundings.
Contrast effects
Josef Albers and Itten's seven contrasts - hue, light–dark, cold–warm, complementary, simultaneous, saturation and extension - explain why a colour changes on a different ground. Simultaneous contrast means a mid-grey looks warm on blue and cool on orange. Judge a mixed colour only against the neighbouring area, never on the palette alone.
Local versus observed colour
Local colour is what the object 'is'; observed colour includes the light source, reflected light, aerial perspective and colour constancy. Warm light produces cool shadows; an overcast sky flattens value and cools saturation.
Paint layers
Fat over lean: more oil in each successive layer or the surface cracks. A grisaille or verdaccio underpainting fixes value before colour. Glazing is transparent, tinted medium over a dry light layer; scumbling is a thin opaque veil dragged over a darker layer; impasto is loaded, structural paint; broken colour places unmixed strokes side by side so they optically fuse at a distance.
Worked example
A white plaster cast against a cream wall. Squint: the shadow is two steps darker than the wall. Isolate the shadow with a paper viewing hole - it reads blue-violet against the warm cream. Mix ultramarine with a little burnt umber and white, keeping it lighter than the cast shadow on the table, which stays cool grey. Check the swatch on the canvas, next to the wall, not on the palette.
Traps that cost marks
Darkening with black; mixing four pigments into mud; adding white to 'brighten' and losing chroma; painting every area with the same edge quality; wet-in-wet lean paint under oily paint; matching colour under a different light from the exam room's.