tl;dr: The author built a custom color space (TUV) for representing diverse skin tones by manually labeling RGB colors, applying principal component analysis to align the data along meaningful axes, then hand-fitting spherical equations in Desmos to map the resulting shape. The three PCA-derived axes conveniently correspond to deep/fair, flushed/ochre, and cool/warm, and a single radius parameter (R²) lets you tune variation for pickers or procedural generation. Includes Python/JS sample code, an interactive picker, and candid acknowledgment of the unscientific "guess and check" methodology.