Illumination methods and apparatus, in which a first number of first light
sources are adapted to generate first radiation having a first spectrum,
and a second number of second light sources are adapted to generate
second radiation having a second spectrum different than the first
spectrum. In one example, the first number of the first light sources and
the second number of the second light sources are different. In another
example, a first intensity of the first radiation and a second intensity
of the second radiation are independently controlled so as to
controllably vary at least an overall perceivable color of generated
visible radiation. In yet another example, a first control signal
controls all of the first light sources substantially identically, and a
second control signal controls all of the second light sources
substantially identically.