PRIZM 4.0DSTA
Viewing C3 design language
RC3 · Colour

Ember

RC3’s signature colour. Red-orange at hue 32 in OKLCH. Ramp, token mapping, activation, and contrast receipts.

Ramp

Eleven steps in OKLCH. Mirrors styles/tokens/rc3-light.css and styles/tokens/rc3-dark.css.

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 StepOKLCH
--prizm-rc3-50oklch(97% 0.024 32)
--prizm-rc3-100oklch(93% 0.060 32)
--prizm-rc3-200oklch(86% 0.118 32)
--prizm-rc3-300oklch(78% 0.165 32)
--prizm-rc3-400oklch(71% 0.195 32)
--prizm-rc3-500oklch(63% 0.200 32)
--prizm-rc3-600oklch(55% 0.180 31)
--prizm-rc3-700oklch(47% 0.150 30)
--prizm-rc3-800oklch(40% 0.120 29)
--prizm-rc3-900oklch(33% 0.092 28)
--prizm-rc3-950oklch(25% 0.065 27)

Token mapping

The override layer touches only the accent semantic tokens. Surface, fg, border, status, and glass tokens inherit from C3 verbatim.

Dark mode
--prizm-color-accentvar(--prizm-rc3-400)
--prizm-color-accent-hovervar(--prizm-rc3-300)
--prizm-color-accent-fgvar(--prizm-slate-950)
Light mode
--prizm-color-accentvar(--prizm-rc3-700)
--prizm-color-accent-hovervar(--prizm-rc3-800)
--prizm-color-accent-fgoklch(100% 0 0)

Activation

RC3 surfaces opt in by setting data-pack="rc3" on the scope element. Token files gate on the composed selector:

[data-zone="c3"][data-mode="dark"][data-pack="rc3"] { ... }
[data-zone="c3"][data-mode="light"][data-pack="rc3"] { ... }

The App Shell sets the attribute when an RC3 app is active. The custom-element wrapper sets it on the shadow root when RC3 embeds in a legacy host.

Contrast — WCAG AA

Computed with the same OKLCH→sRGB→WCAG path as scripts/audit-contrast.ts. Eight accent pairings, all clearing AA with margin.

ModePairingRatioTargetStatus
darkaccent (rc3-400) on bg7.20:14.5:1PASS
darkaccent (rc3-400) on surface5.29:14.5:1PASS
darkaccent-fg (slate-950) on accent7.04:14.5:1PASS
darkaccent-hover (rc3-300) on bg9.01:14.5:1PASS
lightaccent (rc3-700) on bg6.83:14.5:1PASS
lightaccent (rc3-700) on surface7.36:14.5:1PASS
lightaccent-fg (white) on accent7.36:14.5:1PASS
lightaccent-hover (rc3-800) on bg9.06:14.5:1PASS