Development of a lip colour chart across four ethnicities.

In the human face, the lips play a key role in social interactions and are a major element of makeup strategies. However, the amount of data available on lips, particularly relating to colour, is limited in comparison to that on skin. To gain a better understanding of lip colour, this study aimed to assess its diversity across four ethnicities (Asian Chinese, African American, Hispanic American and Caucasian American and French). The final objective was to develop a lip colour chart to guide cosmetic product development. A total of 514 women aged from 19 to 68 years were recruited in the USA, France and China. Their natural lower lip colour was measured with a full-face hyperspectral imaging system, SpectraFace® (Newtone Technologies, Lyon, France). The data showed a large variety in lip colour between and within each ethnicity. Important overlaps were found between ethnic groups, particularly and surprisingly between Hispanic and Asian women. This allowed for the development of a lip colour chart composed of 53 lip tones, based upon lightness and hue, as a global reference guide for lip colour assessment. Hispanic women showed the largest diversity, represented in 32 of the chart tones. The present study revealed a large lip colour diversity across four ethnic groups. The inter-group overlaps demonstrate that lip colour is not solely defined by individual ethnic belonging. The 53 lip tones described here could be used as target shades to create more inclusive nude lipsticks in the near future.