A pure colour is a monochromatic colour.
- Each wavelength of light at full saturation and brightness is perceived as a pure colour.
- A monochromatic colour is a colour produced by a single wavelength of light.
- Colours produced by a narrow band of adjacent wavelengths often appear to be pure colours.
- Spectral colours are the pure colours associated with a natural rainbow.
- Natural rainbow colours include red, orange, yellow, green, blue and violet but the human eye can distinguish many thousands of other pure colours as well as each of these.
- In a continuous spectrum of sufficiently close wavelengths, separate colours are indistinguishable.