Ultraviolet Light

The color of light is directly related to its wavelength. Or to its frequency. (These two are directly related to each other and are based on the speed of light through a vacuum). Raising the frequency shortens the wavelength, and lowering the frequency increases the wavelength. Typically, though, we discuss the wavelength of a particular light, rather than the frequency.

254nm UV has (in the UVC range) is particularly effective in sterilization, because it breaks up the DNA in microorganisms. It has a quantum energy of 4.9 electron volts per photon.

254nm LED's are somewhat rare, though, and usually mercury vapor lamps are used to make germicidal lamps.