The light we see in a microscope comes from the light source. This is made up of the lamp, power supply and lamp housing. Each one of these must be designed to work with the others. The lamp must have the correct power supply and the lamp housing must be designed for the lamp. The lamp used in a microscope is rated by amount and by color.
Amount is rated in lumens, the more lumens the better.
Color is rated by the spectrum the lamp produces and by the Kelvin temperature of the lamp. A lamp can emit a continuous spectrum of light or a discontinuous spectrum. A continuous spectrum means that there is light produced at each point in the visible spectrum and that the spectrum line is a curve, not a series of hills and valleys. A discontinuous spectrum means that there are areas in the visible were no light is produced. An example of this would be the Mercury burner arc source.