Derive, Optimise and Audit a Scientific Colour Palette from One Seed Colour R package palettecore version 0.4.1 Generates sequential, diverging and categorical colour palettes from a single seed colour in OKLCH (the cylindrical lightness-chroma-hue representation of the Oklab perceptual colour space), with spacing measured by the CIEDE2000 colour-difference formula of the International Commission on Illumination. Audits every palette under simulated colour-vision deficiency, greyscale conversion, the standard Red Green Blue (sRGB) gamut and Web Content Accessibility Guidelines (WCAG) contrast. Colour-vision deficiency is simulated at severity 1.0 with the model of Machado, Oliveira and Fernandes (2009) <doi:10.1109/TVCG.2009.113>; the design rationale follows Crameri, Shephard and Heron (2020) <doi:10.1038/s41467-020-19160-7>. Mirrors the 'Python' reference implementation maintained in the same repository and is validated against shared parity fixtures. Thresholds are configurable design rules, not established accessibility cut-offs. Software Depends: R (>= 4.1) Imports: stats, utils Suggests: ggplot2, jsonlite Heidi Helena Andersén <andersenheidihelena@gmail.com> Comprehensive R Archive Network (CRAN) Heidi Helena Andersén [aut, cre] (ORCID: <https://orcid.org/0000-0001-5923-5865>) Apache License (>= 2) 2026-08-09 application/tgz https://CRAN.R-project.org/package=palettecore doi:10.32614/CRAN.package.palettecore