The optical absorption and photoluminescence properties of CdSe and Mn-doped ZnSe quantum dots will be reviewed. When incorporated as the active layer in an electrochemical cell, it will be shown that the photoluminescence of these materials can be increased (“electrobrightening”) or decreased (“Auger quenching”) by filling selected electronic states through the application of an appropriate bias. Finally, results on a mixed CdSe/Mn:ZnSe sample will be presented whose photoluminescence can be tuned from green to orange with applied bias.