We present the hybridization of CdSe/ZnS core-shell nanocrystals (NCs) on InGaN/GaN based blue/near-UV LEDs to generate light widely tunable across the visible spectral range and especially within the white region of the CIE (1931) chromaticity diagram. We report on the design, growth, fabrication and characterization of these hybrid NC-LEDs. In 26 NC-LED samples, we experimentally show the effect of the NC concentration and NC film thickness on tuning the colour properties of the generated light (tristimulus coordinates, colour rendering index and correlated temperature) and further compare layer by layer assembly and blending of NCs for integration in LEDs. With greatly tunable colour properties, these hybrid white light sources hold promise for future lighting and display applications.