The urgent demand for alternative light source in an illumination and display area has led to the rapid advancement of white light emitting diodes (LEDs). A blue LED can serve as a primary light component, pumping photoluminescence of a broad band emission phosphor such as yellow Y 3Al 5O 12:Ce 3+ (YAG:Ce). Various YAG:Ce nanocrystalline phosphors, where a red-emitting Pr 3+ ion is codoped with Ce 3+ ion in the YAG host and some Y 3+ or Al 3+ sites are substituted with Gd 3+ or Ga 3+ ions, respectively, have been synthesized via a novel soft chemistry using citric acid and poly (vinyl pyrrolidone) (PVP). Codoped Pr 3+ ion exhibited its characteristic red line peaks, and the Ce 3+ emission was blue- and red-shifted by respective Ga 3+ and Gd 3+ substitution due to a modified crystal field splitting. These spectral variations caused by a codopant and substituents can lead to the manipulation of CIE color coordinates of the emission. This tunability would contribute to an improved color gamut of white LEDs, particularly for backlighting liquid crystal display. White LEDs were fabricated by coating these nanophosphors on blue LEDs and characterized.