White light‐emitting diodes (WLEDs), known for their high brightness, high efficiency, and long lifetime, are widely utilized in the backlight of liquid crystal displays. However, it is still difficult to improve the color gamut of WLEDs while maintaining the L50 lifetime. The luminous characteristics of WLEDs employing different combinations of quantum dots and phosphor are investigated in this work. Additionally, investigations on the L50 lifetime for WLEDs are carried out by employing a two‐step accelerated stress method. Finally, an ensemble machine learning model is proposed to predict the L50 lifetime of WLEDs, achieving high predictive accuracy with R2 of 0.986.