LED voltages lends to different colors?

[Robin07]

I heard through the grape vine that applying different voltages will emit different colors of light from an LED mainly red, green, white and blue. Is this accurate or is it that the architecture of each LED is different. Are there LEDs that are sensitive to various voltages? If so what would these be called?

 

[dlgoff]

The colors of the LEDs are determined by their semiconductor materials which determines there operating voltage.

Check out this http://en.wikipedia.org/wiki/Light-emitting_diode#Colors_and_materials"