The light sources with high color rendering index (CRI) have diverse operating occasions including indoorillumination, backlight, mirror lamp, decorative lighting, etc. The conventional fluorescence dopants have advantages of high color quality and stability, which are favorable to increase CRI of WOLEDs, but often encounter the problem of inferior EL efficiencies due to low exciton utilization. The out-of-phase sensitization system was previously demonstrated as an effective approach to sensitize conventional fluorescence dopants with reduced exciton loss for WOLEDs. Herein, a novel design of out-of-phase sensitization configuration on the basis of above sandwich configuration of two-color devices is proposed for three-color WOLEDs to have a higher CRI. Three-color white EMLs consisting of 1 wt% DBP: TCP-BP-SFAC (14 -x nm)/1.5 wt% 4CzTPNBu: TCP-BP-SFAC (x nm)/TCP-BP-SFAC (6 nm) are prepared, in which x is 5, 4 and 3 for devices W2-1, W2-2 and W2-3, respectively (Fig. ). Different from the sandwich configuration, one of the TCP-BP-SFAC layers is doped with red fluorescence DBP to form a red EML to improve CRI. This red EML is envisioned to be sensitized by adjacent orange EML through FET to obtain high EL efficiencies. The detailed EL performance of W2-1~W2-3 are displayed in Fig. , Supplementary Fig. and Table . The CRI is successfully increased from 65 of W2-1 to 71 of W2-3, which is close to those of normal lighting devices. Inspiringly, W2-1 achieves remarkable EL performances with a PE of 106.8 lm W -1 and an EQE of 30.8%. W2-2 and W2-3 also exhibit excellent EL performances, with PEs and EQEs of 99.7 lm W -1 and 29.1%, and 92.4 lm W -1 and 29.6%, respectively. Like two-color WOLEDs, these three-color WOLEDs also hold high efficiency stability. The PEs of W2-1, W2-2 and W2-3 are maintained at 80.6, 83.0 and 72.8 lm W -1 at 100 cd m -2 , and 52.6, 58.2 and 48.2 lm W -1 at 1000 cd m -2 , respectively, disclosing these devices are amongst the best threecolor WOLEDs (Fig. and Supplementary Table ). To decipher the sensitization process, a supplementary device WS3 with an EML of 1 wt% DBP: mCP (5 nm)/1.5 wt% 4CzTPNBu: TCP-BP-SFAC (14 nm)/TCP-BP-SFAC (6 nm) is fabricated, which is coincident with the reported out-of-phase sensitization design (Supplementary Fig. and Supplementary Tables and). WS3