Visible light comprises only a tiny portion of the entire electromagnetic spectrum of radiation.
The wavelengths that we are able to see lie between 400 and 700 nanometers in length. As we have discussed in the section on frequency and wavelength , all electromagnetic radiation is the result of the decay of photons and gamma rays from atoms. When venturing outside, a vast majority of the light we see is emitted from the sun, which also emits many other frequencies of radiation that do not fall in the visible range. Quantification of color is a useful relationship that makes it easy to differentiate between different hues and shades. It is possible for many different spectral distributions to produce identical color sensations.