Ambient light that is modified for use in a projection system is described. In an embodiment of the present invention, a projection system includes a projection screen and an ambient light source. The projection screen reflects and/or emits one or more ranges of wavelengths of visible light. The projection screen also absorbs visible wavelengths of light in at least one other range that is not included in the one or more ranges. The ambient light source outputs visible wavelengths of light in the at least one other range. The at least one other range of wavelengths have a greater intensity as weighted by the sensitivity of a human eye than that of the wavelengths of light output by the ambient light source in the one or more ranges.