<P> The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye . Electromagnetic radiation in this range of wavelengths is called visible light or simply light . A typical human eye will respond to wavelengths from about 390 to 700 nanometers . In terms of frequency, this corresponds to a band in the vicinity of 430--770 THz . </P> <P> The spectrum does not contain all the colors that the human eyes and brain can distinguish . Unsaturated colors such as pink, or purple variations like magenta, for example, are absent because they can only be made from a mix of multiple wavelengths . Colors containing only one wavelength are also called pure colors or spectral colors . </P>

Which part of the em spectrum is visible to humans