High-performance white light-emitting diodes (WLEDs) hold great potential for the next-generation backlight display applications. However, achieving highly efficient and stable WLEDs with wide-color-gamut has remained a formidable goal. Reported here is the first example of pure red narrow bandwidth emission triangular CQDs (PR-NBE-T-CQDs) with photoluminescence peaking at 610 nm. The PR-NBE-T-CQDs synthesized from resorcinol show high quantum yield (QY) of 72% with small full width at half maximum of 33 nm. By simply controlling the reaction time, pure green (PG-) NBE-T-CQDs with high QY of 75% were also obtained. Highly efficient and stable WLEDs with wide-color- gamut based on PR- and PG-NBE-T-CQDs was achieved. This WLED showed a remarkable wide-color gamut of 110% NTSC (National Television System Committee) and high power efficiency of 86.5 lumens per watt. Furthermore, such WLEDs demonstrate outstanding stability. This work will set the stage for developing highly efficient, low cost and environment-friendly WLEDs based on CQDs for the next-generation wide-color gamut backlight displays.