Fig. 1. Sampling Position in the Fengxian Hall
(a): Pigment 1; (b): Pigment 2; (c): Pigment 3; (d): Pigment 4; (e): Pigment 5; (f): Pigment 6

Fig. 2. Cross-section microstructure, SEM images and Raman spectra of red pigments
(a): Microstructure of sample 1; (b): Microstructure of sample 2; (c): SEM images of sample 1; (d): SEM images of sample 2; (e), (f), (g): Raman spectra of sample 1; (h): Raman spectra of sample 2

Fig. 3. Cross-section microstructure, SEM images and Raman spectra of green pigments
(a): Microstructure of sample 3; (b): Microstructure of sample 4; (c): SEM images of sample 3;(d): SEM images of sample 4; (e): Raman spectra of sample 3; (f): Raman spectra of sample 4

Fig. 4. Cross-section microstructure, SEM images and Raman spectra of blue pigments
(a): Microstructure of sample 5; (b): Microstructure of sample 6; (c): SEM images of sample 5;(d): SEM images of sample 6; (e): Raman spectra of sample 5; (f): Raman spectra of sample 6