Colour Theory and Colour Schemes in Interiors
What this domain tests
Colour questions ask you to name the harmony, justify it against the light and function of the room, and specify colours in a recognised system (NCS, RAL, Munsell). Vague answers such as "warm colours" without a system reference or a reason usually score in the lower band.
The wheel and the dimensions of colour
- Traditional artist's wheel: primaries red, yellow, blue; secondaries orange, green, violet; tertiaries between them.
- Additive (light) primaries are red, green, blue; subtractive (print) are cyan, magenta, yellow.
- Every colour has hue, value (lightness) and chroma (saturation); adding white makes a tint, black a shade, grey a tone.
Harmonies
- Monochromatic: one hue, varied value and chroma - calm but flat unless texture is added.
- Analogous: two or three adjacent hues - restful, low contrast.
- Complementary: opposite hues - maximum contrast; one dominant and one accent avoids optical vibration.
- Split-complementary: one hue plus the two neighbours of its complement - contrast with less tension.
- Triadic: three evenly spaced hues - lively, best with one clearly dominant.
- Accented neutral: a neutral field plus one saturated accent, the safest scheme in small rooms.
Systems, light and meaning
- NCS notation reads blackness, chromaticness, hue: S 1502-Y is 15% blackness, 2% chromaticness, yellow hue.
- RAL Classic is used for paints and lacquers (RAL 9010 pure white).
- LRV (light reflectance value): ceilings 80+, walls 60–80 in low-light rooms.
- Light changes colour: north-facing rooms receive cool bluish daylight (about 6,500 K), so warm-based neutrals balance it; metamerism makes two samples match in a shop and clash in daylight.
- Cultural associations matter in Cyprus: lime-white walls, blue-painted joinery and doors, the blue "mati" bead against the evil eye.
Worked example
A north-facing living room of 18 m² with one window and a 2.70 m ceiling. Walls in NCS S 1005-Y20R warm off-white (60%), mid-tone sage-green upholstery and curtains (30%), deep teal cushions and one artwork (10%). Reasoning: the warm base counteracts the cool north light and keeps LRV high in a room with limited glazing; sage and teal are analogous (green–blue), giving unity; the teal's much lower value supplies the contrast that a complementary pair would have supplied too aggressively; 60-30-10 keeps the accent at 10%, so it reads as emphasis rather than noise.
Traps that cost marks
- Calling analogous colours complementary, or a tint a shade.
- Specifying a saturated complementary pair at equal areas, producing vibration.
- Matching samples under shop lighting only, ignoring colour temperature and metamerism.
- Ignoring ceiling LRV in corridors and rooms without daylight.
- Painting small rooms entirely dark for "cosiness" and losing light without compensating with pale floors.