Charcoal is the base: text, wordmark, primary buttons.
Yellow is an accent – NEVER a load-bearing surface or background colour.
Backgrounds: off-white (color.background.base).
Yellow never carries text or an icon on a light background (contrast 1.33:1
against background.base – illegible). Focus rings are charcoal, not yellow.
The accent yellow is locked physically first. Pick it against a Pantone
fan deck and lab dips, then derive the hex – never the other way round. A
yellow chosen on screen may turn out impossible to dye, outside CMYK gamut,
or without a usable embroidery thread. By then it is already in the site,
Shopify, Klaviyo and Figma, and has to be picked again.