We report white light generation by hybridizing green-red emitting (CdSeZnS/CdSe (core) shell/ shell quantum-dot-quantum-well heteronanocrystals on blue InGaN/GaN light emitting diodes with the photometric properties of tristimulus coordinates (x, y) =(0.36, 0.30), luminous efficacy of optical radiation LE= 278 lm/W, correlated color temperature CCT= 3929 K, and color-rendering index CRI= 75.1. We present the photometric analysis and the quantum mechanical design of these dual-color emitting heteronanocrystals synthesized to achieve high-quality white light when hybridized on light emitting diodes. Using such multicolor emitting heteronanocrystals facilitates simple device implementation while providing good photometric properties