Sources & References
Standards & specifications
WCAG 2.x contrast & relative luminance
The relative luminance and contrast ratio formulas behind the contrast checker and every color page's AA/AAA badges follow the W3C specification exactly.
w3.org/TR/WCAG21 →CSS Color Module (named colors)
All 148 names in CSS Color Names and every “nearest named color” match come from the W3C/WHATWG named-color keyword list, not a hand-typed subset.
w3.org/TR/css-color-4 →Published research
CIEDE2000 (Sharma, Wu & Dalal, 2005)
The Delta E calculator's CIEDE2000 mode is validated against the paper's own published test-pair dataset — the reference values color-science software is checked against industry-wide.
Sharma, G., Wu, W., & Dalal, E. N. (2005). “The CIEDE2000 color-difference formula.” Color Research & Application, 30(1), 21–30.Brettel, Viénot & Mollon (1997) color vision deficiency simulation
The color blindness simulator's linear-RGB transformation matrices for protanopia, deuteranopia, and tritanopia come from this paper's model of dichromatic vision.
Brettel, H., Viénot, F., & Mollon, J. D. (1997). “Computerized simulation of color appearance for dichromats.” Journal of the Optical Society of America A, 14(10), 2647–2655.OKLab (Björn Ottosson, 2020)
The OKLab/OKLCH conversions behind the color mixer and every perceptually-even scale on this site implement Ottosson's published derivation directly.
bottosson.github.io/posts/oklab →Reference datasets
Tailwind CSS default palette
Every shade in the color chart's
Tailwind section is read from the installed tailwindcss npm package itself.
Material Design classic color palette
The Material Design Colors page was verified hex-by-hex against MUI's open-source mirror of Google's original specification.
github.com/mui/material-ui →Bootstrap 5 color variables
The Bootstrap Colors page
reads its base colors, theme roles, and gray scale straight from Bootstrap's own scss/_variables.scss.
Google Fonts metadata
The Fonts library's family list, weights, subsets, designers, and popularity ranking come from Google Fonts' own metadata, snapshotted July 2026.
fonts.google.com/metadata/fonts →How this list stays honest
Every implementation checked against a source above has an automated test asserting it matches — so this page can't quietly drift out of sync with the code the way a one-time “About” paragraph might. If you find a formula on this site that doesn't match its cited source, tell us — that's a bug report we'll act on immediately.
See it for yourself
Every formula cited here backs a real, working tool — not just an explanation.