principle. colour is seasoning, not structure. hierarchy is built from neutral contrast — white at opacities on dark, weight and spacing before hue — so that the one hue on a surface is spent only where it means something. a hue that means something means the same thing on every surface, and is never reassigned decoratively.

rule (law, tokenised in tokens/core-v1.md).

• tint ceiling: accent tint on surfaces is capped at 0.08 alpha, enforced where themes are applied, not left as a default someone can raise past.
• no solid accent fills, with exactly two exceptions: a primary action button, which uses the muted step of the hue, and a switch in its on state (recorded as a candidate exception in the linter flags).
• chips: inactive = accent at 0.10 background, border token, primary text. active = accent at 0.14 background, a 1px accent ring at 0.45, semibold primary text.
• pills and badges: background at or under 0.16, border at or under 0.35 or none, text in the accent at full muted strength.
• selection: a selected object is outlined in the accent at 0.85, 1.5px; unselected objects take the border token.
• two hues maximum on any surface: the governing hue plus at most one state colour (danger, or sage as success — themselves muted). the accent picker is the one lawful exception: it is a picker, so it shows the muted set, at small swatch size, ring-selected in text primary.
• data hues are data. chart series take ramp hues in ramp order; identity hues on miniatures are shown only where the depicted thing is itself the subject. neither is a licence to decorate chrome.

worked example. a scene chip in its active state was once a solid fill of its scene’s hue: one red scene turned the row into a red pill at full strength. under the law the same chip is a 0.14 tint of the muted hue with its 0.45 ring and semibold text — legible, calm, and incapable of shouting over the canvas it sits above. the primary action beside it may be solid, in the muted step only: that scarcity is what makes the solid read as “primary” at all.

Pairs, not prose: the same element under the law and against it. the specimens are live, rendered from the token source.

Canonical text: §3, colour and the accent law, in the design language document. Governed by decisions 0001 and 0014; values in tokens/core-v1.md.