Sequential — magnitude, one hue

Diverging — polarity, neutral midpoint

Rules

Brand blue means “interactive” everywhere else in this system, so a chart painted in six blues would make every series look clickable. The other six hues appear nowhere but charts.

Status colors are reserved — never a series, and a series color never means “bad”.

Text wears ink tokens, never its series color; a colored mark sits beside it instead.

Dark mode is a re-picked set against the navy surface, not a mechanical lightening.

npm run check:palette re-proves the lightness band, chroma floor, protan/deutan/tritan separation, normal-vision floor and contrast on every CI run.