Fig. 1. Relative spectral energy distribution of five-color LEDs

Fig. 2. Relationship between duty cycle and power of different light sources. (a) R; (b) G; (c) B; (d) WW; (e) CW

Fig. 3. Flow chart of multi-channel light mixing

Fig. 4. Schematic diagram of color coordinates. (a) Color coordinates of R and G; (b) color coordinates of the mixing point

Fig. 5. Color coordinates of the three primary colors

Fig. 6. Chromaticity coordinate range under different step lengths. (a) R, G, and B steps are 5; (b) R and G steps are 10, B steps are 5

Fig. 7. Color coordinate range under different combinations. (a) R and WW color coordinates; (b) mixed point color coordinates

Fig. 8. Color coordinates of five-color LEDs

Fig. 9. Schematic diagram of the experimental module connection

Fig. 10. Physical diagram of the experimental module

Fig. 11. Light source module inside the panel lamp

Fig. 12. Physical map of HAAS-2000 spectrum analyzer

Fig. 13. Coordinates of sampling points

Fig. 14. Variation curve of color rendering index R_a and LER at different color temperatures

Fig. 15. Value range of R when R_a>90

Fig. 16. Color coordinates of the mixed point with R_a > 90

Fig. 17. Ellipse with a color tolerance of 5 at different color temperatures

Fig. 18. Color tolerance ellipse of RGB and WW combinations at different color temperatures. (a) 3000 K; (b) 3500 K; (c) 4000 K; (d) 5000 K; (e) 6500 K

Fig. 19. Color tolerance ellipse of RGB and CW combinations at different color temperatures. (a) 4000 K; (b) 5000 K; (c) 6500 K

Fig. 20. Color rendering index of spectra under different combinations

Fig. 21. LER of spectra under different combinations

Fig. 22. Spectral energy distribution of blackbody radiation at different color temperatures