The property characterising visible light of varying wavelengths, the colour of something being the wavelength of the light reflected by it; primary colours are red, blue and yellow/green, meaning that combinations of these are able to produce the rest of the shades in the spectrum, secondary colours being those composed of equal parts of two primaries; complementary colours are those on opposite sides of a colour wheel, a radial arrangement of the spectrum with the three primaries arranged at 120 degrees, thus emphasising the colors' interrelations; a pure hue is a particular wavelength of light, i.e. A specific color; a tint is a pure (or completely saturated) hue with white added, a shade a hue with black added; both terms denote possible changes of a given hue's value, i.e. How light or dark it is, as (subtly) distinct from its intensity, which indicates how bright or dull a hue is. A colour scheme refers generally to the range and combination of colours in a given artwork, otherwise known as a palette.