(a reference) 

          INCANDESCENT (YELLOW) LIGHT

                               Incandescent lights are mainly used in houses and small shops. It gives off a yellow-tinged light.

                                    FLUORESCENT LIGHTS   

                                Florescent lights are usually used in big shops, buildings and sometimes houses. they are very bright. Some researches say they may cause cancer...

                                                 SUNLIGHT

                               The sun has been a natural light for a long, long time. It's main use is to see and to create energy.

                                    ULTRA-VIOLET LIGHT 

                               Ultra-violet lights are used most of the time for disco dances, disco bowling and tanning booths. It gives off a purple glow and makes white objects glow in the dark.