Colour / accent law
LAW — locked, CI-gatedColour / accent law
Section titled “Colour / accent law”principle. hierarchy is built from neutral contrast, not from hue. white at opacities on dark, weight and spacing before hue, so 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, and it can’t compete with the canvas it sits above. the primary action beside it may be solid, in the muted step only: it’s the only solid on the surface, which is why it reads as “primary”.
the law, shown
Section titled “the law, shown”Pairs, not prose: the same element under the law and against it. the specimens are live, rendered from the token source.
do
the accent sits on the surface as a tint. the surface itself stays neutral, so the chip and the button can still be read at a glance.
don't
eveninga solid fill spends the whole surface on one word, and leaves nothing for the one button that is allowed it.
do
one hue governs. the sage beside it is a state colour — the second and last hue a surface may carry.
don't
three hues competing for governance: with everything accented, nothing on the surface can mean anything.
do
a day that was never fetched is a gap in the line. the chart stops where the data stops.
don't
drawn as zero, the missing day becomes a measurement nobody made.
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.