The best possible lighting we can offer our students is daylighting. Is energizes, has blue in it's spectrum in the main part of the day and energizes. The color temperature of the light sources, when showing videos and presentations, can be varied so the classroom doesn't seem fit for sleeping. This can be accomplished by bringing in some inexpensive lamps from a discount store and placing them in the back of the room. The halo effect works well and the screen is clearly visible. Don't be afraid to use colored bulbs for that "gone to the movie" experience for students.