Electro magnetic
radiation in the wavelength range of 380 nm to 730 nm is seen as light by our
eyes. Low wavelengths show as blue light. Then the spectrum continues from
green, yellow, orange to red.
UV radiation is located in the range underneath 380 nm; the range above 730 nm is
called infrared radiation.
The visual
impression of a colored body changes by the composition of the incoming light.