A non-spectral colour is a colour that is not present in the visible spectrum and cannot be produced by a single wavelength or narrow band of wavelengths of light.
- While spectral colours are evoked by a single wavelength of light in the visible spectrum, non-spectral colours are produced by a combination of spectral colours from different parts of the spectrum.
- Colours evoked by a single wavelength of light are often described as being produced by monochromatic light.
- Magenta is an example of a non-spectral colour. It is produced by combining blue and red, two colours that are not adjacent in the visible spectrum.
- When we look around us, the colours of things we see rarely include pure spectral colours but are more likely composed of narrow bands of contiguous wavelengths.
- Non-spectral colours are produced on digital screens and by digital printers by mixing colours from different parts of the visible spectrum.
- The RGB colour model generates a complete range of colours on TVs, computers and phones by blending the primary colours (red, green and blue) in varying proportions..
- The CMY colour model produces a full spectrum of colours by combining the primary colours of cyan, magenta, and yellow in varying proportions.
Related diagrams
Each diagram below can be viewed on its own page with a full explanation.
