The tool separates photo screening from color scoring. Your browser checks that exactly one face is centered and front-facing, then resizes and converts the photo on your device. After you consent and start, only the full normalized pixel image is uploaded privately for sampling on the forehead, cheeks, and jaw.
Accepted pixels are converted from sRGB to CIELAB, a color space designed to compare perceptual color differences. A versioned scoring map then places the measured lightness, warmth, and chroma near one of 12 seasonal profiles. The top-two gap is a score separation, not a probability or accuracy percentage.