Colour Theory and Application: Wheel, Harmony, Mixing, Media
The paper tests terminology, mixing logic and the practical behaviour of pigment in different media.
The wheel
Subtractive pigment mixing uses red, yellow and blue primaries; secondaries are orange, green and violet; tertiaries mix a primary with a neighbouring secondary. Complementary pairs sit opposite and neutralise each other. Harmonies: analogous, complementary, split-complementary, triadic, tetradic and monochromatic. Additive mixing with light uses red, green and blue, with cyan, magenta and yellow secondaries - the two systems are not interchangeable.
Dimensions of colour
Hue is the family name, value is lightness, chroma is saturation. A tint adds white, a shade adds black, a tone adds grey or the complement.
Mixing rules
Add dark to light for large value shifts; lower chroma with a touch of complement rather than black, which greys and deadens. Never mix more than three pigments or the result muddies. Watercolour works light to dark with transparent glazes, reserving bare paper for white; gouache and poster colour are opaque and can be worked dark to light; oil follows fat-over-lean; acrylic dries darker than it looks wet.
Optics
Warm hues advance, cool recede. Simultaneous contrast pushes a colour toward the complement of its neighbour. Pointillism used optical mixing, letting the eye fuse adjacent dots.
Worked example
Dulling a too-bright red: add a trace of green, its complement, rather than black, which would kill the chroma. Then adjust value with a tint of that same red rather than white if you need to keep it saturated.
Traps
Using black to darken; judging colour under tungsten or tube light; over-mixing; adding white to watercolour; confusing the RYB and RGB primaries.