Proposed Shade Guide for Human Facial Skin

Objectives: The purpose of this study is to determine the color coordinates for an optimum proposed skin shade guide. Methods: A spectroradiometer and an external light source were configured in a noncontacting 45/0-degree (45-degree illumination and 0-degree observer) optical configuration to measure the color of subjects' facial skin (tip of nose and upper lip). The 120 subjects were stratified into 5 age groups (18-29; 30-39, 40-49, 50-59, 60-85) with 4 racial categories (White, Black, Asian and Others) and balanced for gender. Measurements were taken between 380-780 nm at 2 nm bandwidth intervals. The data were converted to CIE L*a*b* color coordinates. A repeated measures analysis of variance was used to identify skin color contributions from race, age, sex and location. A hierarchial clustering analysis was used to identify color groups that clustered together. Results: The two greatest contributors to L*a*b* measurements of facial skin color differences were race and location of color measurement on the face (both p<0.01). It was interesting that b* was affected by all factors (p<0.05). Age only affected b* (p<0.01), while gender affected L* (p<0.05) and b* (p<0.05). Cluster analysis results revealed five cluster centroids with mean L*a*b* as follows: (1=52.5, 17.0, 18.9), (2=37.7, 17.2, 14.7), (3=49.4, 22.0, 12.3), (4=41.5, 25.5, 13.3), and (5=26.7, 14.6, 14.7). Conclusions: L*a*b* was significantly affected by race and location. b* was significantly affected by all factors. Clustering analysis was able to identify clusters in 120 patients for 5 skin tones.

Supported in part by NIH grants R15 EY013527 and K23 DE016890 to AGW.