A novel process has been developed to create silicon nanoparticles (Si-NPs) that emit controlled colors from blue to the near infrared. The emission is reasonably stable in air. This is the first ever report of a process that can produce the full spectrum of visible light from silicon and the first process that creates air-stable blues, greens, and yellows. The particles are created in a nonthermal silane plasma and the resultant aerosol is sent to a second plasma. The process in this chamber involves simultaneously etching and passivating the nanoparticles using a CF4 plasma. The plasma leaves a coating on the surface that prevents the formation of Si=O bonds that are typically seen after air exposure.