Abstract
Due to the increasing demand for diversity and inclusivity, beauty companies have expanded their liquid foundation ranges to cover a broad spectrum of skin tones and brightness levels. However, discoloration over time remains a concern. This study investigates discoloration trends across 32 foundation shades from four global brands. Foundations were applied to an opacity chart at a thickness of [Formula: see text]m, and color changes were measured over time using a spectrophotometer, reported in the CIE1976L*C*h color space. Our results indicate that discoloration trends depend on foundation lightness, with darker shades exhibiting less [Formula: see text] value reduction than lighter shades within each brand. Additionally, one brand demonstrated superior color retention. Scanning Electron Microscopy (SEM) images-acquired using secondary electron mode-offered qualitative comparisons of surface morphology across formulations. These findings highlight the importance of considering discoloration patterns when formulating foundations tailored to specific market demographics.