OKLCH Color Specification / 100% Strict WCAG 2.1 AAA / 19 Official Ports

Circadia

Perceptually uniform, low-strain themes engineered for continuous focus.

Circadia is an open color specification and multi-platform theme system engineered in OKLCH for cross-platform editors, terminal emulators, and document renderers. Built around human ocular biophysics, circadian light cycles, and strict mathematical accessibility, Circadia delivers 100% Strict WCAG 2.1 AAA contrast (≥ 7.0:1) across all UI and syntax tokens with multi-dimensional Color Vision Deficiency (CVD) support.

Explore:
git clone https://github.com/tanmaymanojgandhi/circadia.git šŸ“‹
ā˜€ļø Warm Parchment
11.69:1 AAA
Daylight Ambient • 300ā€“800+ lux

Glare-free cellulose warm paper canvas (#f7f2e6) engineered for bright daylight environments.

Click to activate ✓ Active
ā˜• Dark Classic
10.26:1 AAA
Warm Candlelight • 0ā€“50 lux

Warm espresso charcoal (#17130f) with glowing ember accents that completely prevent IPS bleed.

Click to activate ✓ Active
šŸ‡ Dark Modern
11.91:1 AAA
Velvet Plum • Modern UI

Deep velvet wine canvas (#140e12) with saturated pastels for modern web and application development.

Click to activate ✓ Active
šŸŒ² Dark Focus
11.02:1 AAA
Obsidian Pine • Deep Terminal

Restorative evergreen moss canvas (#131714) calibrated for deep data science and long terminal sessions.

Click to activate ✓ Active

Tokens & Color Palette

Click any token cell to copy its value.

The 4 Circadian Modes

Engineered in OKLCH to match human melanopic response across ambient light cycles.

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Warm Parchment (Light)

300ā€“800+ lux • Daylight Reading
11.69:1 AAA

Canvas: #f7f2e6 (Warm Cellulose Cast)

Optical Rationale: Eliminates the blinding glare and ocular fatigue of raw #ffffff paper whites. Maximizes daytime cognitive alertness while preserving natural contrast through a deep sapphire text hierarchy.

Anti-Glare Sapphire Headings High Ambient
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Warm Ember & Espresso (Dark Classic)

0ā€“50 lux • Candlelight & Evening
10.26:1 AAA

Canvas: #17130f (Warm Espresso Charcoal)

Optical Rationale: Eliminates IPS backlight halation and blue-light melanopic suppression. Glowing amber accents and warm honey heading elevations create a calming, halation-free evening coding environment.

Melatonin Safe Halation-Free Zero Blue Hazard
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Plum Noir (Dark Modern)

0ā€“50 lux • Velvet Wine & Modern UI
11.91:1 AAA

Canvas: #140e12 (Velvet Wine Noir)

Optical Rationale: Tailored for modern web development, frontend frameworks, and high-DPI OLED screens. Features dusty velvet rose accents and rich lilac/orchid syntax with exceptional clarity.

OLED Optimized Velvet Rose Modern Web Dev
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Obsidian Pine (Dark Focus)

0ā€“50 lux • Deep Terminal & Focus
11.02:1 AAA

Canvas: #131714 (Restorative Evergreen Moss)

Optical Rationale: Calibrated for prolonged data science, long compiling sessions, and deep terminal work. Soft sage and evergreen accents minimize eye strain across 10+ hour continuous flow states.

Deep Terminal Forest Sage Data Science

Multi-Dimensional CVD Separation (Color Vision Deficiency)

Ensuring full usability for Deuteranopia (green-blind), Protanopia (red-blind), and Monochromacy.

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1. OKLCH Luminance Steps (ΔL ≥ 8%)

Instead of relying on fragile hue differences that collapse under CVD, conflicting syntax pairs (e.g. strings vs types vs keywords) are engineered with a guaranteed perceptual lightness delta (ΔL ≥ 8.0%).

Tokens remain instantly distinguishable even in total greyscale or high-contrast monochromacy.
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2. Dual-Channel Typographic Encoding

Keywords and control-flow syntax are systematically rendered with bold font weights across all 20 ports, creating an immediate non-chromatic visual channel for code comprehension.

Zero ambiguity regardless of monitor calibration or color blindness tier.
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3. Quarantined Destructive Red

Saturated alarm red is strictly quarantined for syntax errors, merge conflicts, and linter warnings. Routine syntax never uses red, preventing cognitive alarm fatigue and color confusion.

Alert signals remain authoritative and impossible to overlook.

Mathematical Accessibility (100% Strict WCAG 2.1 AAA)

Every token is verified against mathematical relative luminance invariants.

WCAG 2.1 Relative Luminance Invariant: Contrast Ratio = (Lā‚ + 0.05) / (Lā‚‚ + 0.05) ≥ 7.00:1 (Strict AAA)
56 / 56 Automated Invariants Passed
100% Strict AAA Body & Syntax
0.00% Halation / Blue Hazard
H1 → H6 Monotonic Heading Hierarchy

Syntax Highlight Preview

Perceptually balanced syntax weight across languages.

spec.md
Markdown
Hover a syntax symbol to inspect its token mapping

WCAG 2.1 Accessibility Ratios

Relative luminance verified against canvas background (bg_canvas).

Token Category Sample Hex / OKLCH Contrast Ratio WCAG Invariant

Ports & Ecosystem

18 unified themes for editors, terminals, and tools.

Specification Files

Canonical palette data, normative rules, and token mapping docs.

spec/palette.json Canonical OKLCH and Hex palette definitions
Raw JSON →
spec/rules.md Normative palette and accessibility invariants
Markdown →
spec/token-map.md Semantic mapping guide for port creators
Markdown →