Fig. 6

Summary of medium red color analysis. a Representative color fields for medium-red areas from (left-to-right) Kyōdai no shūgetsu (Autumn Moon of the Mirror) (32.84), Koshikibu no Naishi (32.69), The Departure (2016.18.1), and Ishiyama no shūgetsu (Autumn Moon at Ishiyama) (32.83). b XRF spectra of medium red areas. No identifying elements were detected in these areas. c SERS spectra and corresponding GA fit results for medium red colored areas. Spectrum (i) is from the susuki seedheads on Kyōdai no shūgetsu (Autumn Moon of the Mirror) (32.84), spectrum (ii) is from the orange hakama on Koshikibu no Naishi (32.69), spectrum (iii) is from the futon on The Departure (2016.18.1), spectra (iv) and (v) are from the futon and kimono on Ono no Komachi (32.75), respectively, spectrum (vi) is from the inner kimono on Renshi (32.71), and spectra (vii) and (vii) are from the sake cup and lacquered stand, respectively, on Gi (Righteousness) (35.39). Blue traces are the sample spectra, black traces are the fit spectra, and red traces are the squared difference. The inset plots to the right show the correlation between the sample and its fit spectrum