Establishment of a database for skin color card reflectance and spectra

Objective To construct a database comprising the reflectance spectra, data, and corresponding color and mode parameters using 110 skin color cards from the Pantone Skin Tone Guide (PSTG). Methods The measurement of reflectance spectrum was conducted on 110 internationally recognized skin color cards from the PSTG and the dorsal hand skin of five healthy individuals. Comparative analysis of the reflectance spectra between the color cards and the normal skin was performed. The collected data, images, and parameters of five color models were summarized into a database. Results Significant absorption features were observed in the ultraviolet range of 350-400 nm. In the visible light range of 400-780 nm, the reflectance curves varied with value and chroma, but all exhibited characteristic peaks were around 590 nm. When saturation was constant, a decrease in brightness resulted in reduced reflectance, indicating that lower brightness tends towards black. When brightness was constant, changes in saturation led to increased differences in reflectance, making colors more vivid. The in vivo experiments showed consistent results with the aforementioned observations. Conclusions The reflectance spectra of the color cards are related to the composition and surface structure of the skin. This database can provide valuable data support for medical research, clinical practice, and other related fields.