Multi-chromatic photoluminescent, oxide-capped semiconductor nanocrystals and methods for forming such semiconductor nanocrystals. The method includes exposing one or more oxide-capped semiconductors, preferably type IV semiconductor nanocrystals, to electron beam radiation, wherein the radiation has an energy between 1 and 30 keV, the radiation introducing color centers in the oxide that exhibit photoluminescence in at least the green band of the visible spectrum.