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)