Privacy choices

Hue Codex uses local settings and privacy-aware measurement.

Required storage keeps tools and your local workspace working. Analytics helps improve popular tools; stricter consent regions stay opt-in unless you allow it. Marketing and personalized ads stay off until you choose them.

A polished Hue Codex methodology workspace with color calculation cards, contrast gauges, color-space diagrams, validation panels, standards badges, and export notes.

Methodology

How Hue Codex calculates, ranks, and exports color.

Read the formulas, assumptions, edge cases, validation checks, and limits behind the tools, from WCAG contrast and OKLCH conversion to image extraction and export formats.

WCAG CSS Color 4 CSS Color 5 draft DTCG stable community specification — not a W3C Recommendation Browser-dependent Approximation
Start with contrast Read conversion math Browse tools
11methodology pages
27public tools mapped
v2.0Methodology version
Last updated
WCAGcontrast math
CSScolor syntax

Trust boundary

What is standards-based vs Hue Codex heuristic?

Hue Codex separates external formulas from product guidance. WCAG contrast math and stable CSS color conversion are standards-based; palette ranking, role hints, color-difference bands, and CVD risk labels are Hue Codex heuristics for review.

WCAG CSS Color 4 CSS Color 5 draft DTCG stable community specification — not a W3C Recommendation Browser-dependent Approximation

Standards-based

Standard

Used when an external standard defines the formula, threshold, syntax, or data behavior. Examples include WCAG relative luminance, WCAG contrast thresholds, stable CSS Color 4 conversion behavior, and CSS named color definitions.

Hue Codex heuristic

Hue Codex heuristic

Used when Hue Codex adds product judgment on top of the math. Examples include palette ranking, role hints, highest-contrast candidate recommendations, color-difference bands, image swatch scoring, and color-vision risk labels.

Examples of formula-backed checks versus Hue Codex guidance.
User question Standards-based part Hue Codex heuristic part
Does this text pair pass? WCAG luminance and contrast thresholds decide pass/fail from the raw ratio. Suggested replacement colors rank candidates by search distance and usefulness.
Which palette colors should become roles? WCAG metadata can flag readable foreground/background pairs. Primary, accent, surface, semantic role hints, and palette ranking are Hue Codex guidance.
Are two colors different enough? Delta E 76 and OKLab distance use documented color-space math. Labels such as close variant, distinct palette color, or hue-only risk are review bands.

Color Picker source of truth

Repair, distance, and export contracts.

The Color Picker uses three connected methodology pages. Together they define the role-scoped contrast decision, the bounded OKLab repair objective, and each separately labeled export contract.

Repair 2.0 and contrast

WCAG Hue Codex heuristic

Raw WCAG ratios, alpha compositing, one-to-four-context validation, deterministic tie-breakers, exact sRGB revalidation, and known bounded-search limits.

Read repair methodology

OKLab distance objective

Hue Codex heuristic Approximation

Defines the scaled Euclidean OKLab distance used by the minimal-change strategy and keeps it separate from CIE76 reference values and accessibility claims.

Read distance methodology

DTCG and Tailwind exports

DTCG stable community specification — not a W3C Recommendation Browser-dependent

Separates semantic CSS, Tailwind v4, Hue Codex token-style JSON, DTCG Format/Color, Resolver, legacy JavaScript, reports, and SCSS.

Read export methodology

Global caveats

Known limitations across all tools.

These limits apply across Hue Codex even when a specific tool has more detailed validation notes on its methodology page.

Generated palettes are starting points

Hue Codex heuristic

Palette rankings, role hints, harmony choices, and semantic suggestions help begin a color system, but they still need brand, product, content, and component review.

Contrast is not full accessibility

WCAG Hue Codex heuristic

WCAG contrast ratios are important standards-based checks, but accessible design also depends on typography, layout, state cues, labels, motion, interaction, and assistive technology behavior.

Image extraction is approximate

Approximation Browser-dependent

Extracted palettes depend on sampling, compression, transparency, canvas pixels, browser color management, and the image content selected for analysis.

Print values are not press proofs

Approximation CSS Color 5 draft

CMYK and print-oriented values are communication aids, not press-ready conversions. Final print work needs ICC profiles, stock, ink limits, proofing, and vendor guidance.

Read the complete limitations register Report a calculation issue

Validation resources

Schemas and color-math fixtures for reproducible checks.

Download the public JSON fixture groups used for representative parsing, contrast, conversion, palette, export, and image-sampling regression checks, along with the export schemas and handoff fixtures.

Download export JSON Schema Download export validation fixtures Download Color Picker repair vectors Parsing fixtures Contrast fixtures Conversion fixtures Palette fixtures Export fixtures Image-sampling fixtures

Methodology library

Shared trust pages for the toolset.

Each page supports multiple tools so the formulas, standards, assumptions, validation examples, and caveats stay consistent across Hue Codex.

WCAG W3C Web Content Accessibility Guidelines contrast formulas and thresholds used for accessibility checks.
CSS Color 4 CSS Color Module Level 4 Candidate Recommendation Draft context, plus broadly implemented color syntax and conversion behavior.
CSS Color 5 draft CSS Color Module Level 5 draft features such as color-mix(), light-dark(), contrast-color(), and device-cmyk().
DTCG stable community specification — not a W3C Recommendation Design Tokens Format Module 2025.10 Final Community Group Report. It is stable and intended for implementation, but it is not a W3C Standard, W3C Standards Track document, or W3C Recommendation.
Standard Stable standard or standards-backed behavior used as authority, such as WCAG 2.2 and broadly implemented CSS Color 4 behavior.
Draft standard Draft, candidate, or preview specification material, such as CSS Color 5 features; not treated as final authority.
Hue Codex heuristic Hue Codex ranking, role hints, bands, labels, or workflow guidance rather than an external standard.
Primary source Original or directly maintained source for a dataset, implementation note, package behavior, reference record, or model author page; cited for provenance, not as a standards claim.
Model source Original or model-origin reference for a color model, simulation method, or color-science approach; cited for model provenance, not as a standards claim.
Approximation Model or estimate with known limits, including CMYK, color-vision simulation, image palette extraction, or CSS duotone output.
Browser-dependent Output depends on browser APIs, rendering, color management, canvas pixels, clipboard, download, or CSS support.
Methodology How Hue Codex calculates WCAG contrast The Hue Codex methodology for WCAG contrast, alpha compositing, role scope, legacy HSL repair, and bounded OKLab Color Picker Repair V2.
Standard Hue Codex heuristic Approximation Browser-dependent
Methodology Color conversion, color spaces, and rounding How Hue Codex parses, normalizes, converts, rounds, clamps, and displays HEX, RGB, HSL, HWB, Lab, LCH, OKLab, OKLCH, XYZ, and related CSS color values.
Standard Draft standard Browser-dependent
Methodology How Hue Codex generates palettes and scales How Hue Codex creates harmonies, role-based palettes, tint and shade scales, lightness ladders, warm and cool variants, and accessibility metadata.
Hue Codex heuristic Standard Draft standard Approximation
Methodology Color mixing, opacity, and gradient interpolation How Hue Codex blends colors, composites opacity, generates gradient CSS, samples gradients, and extracts gradient palettes.
Draft standard Standard Hue Codex heuristic Approximation Browser-dependent
Methodology Gamut checks, wide-gamut CSS, and print caveats How Hue Codex treats sRGB source colors, wide-gamut display spaces, CSS color syntax, approximate CMYK, clipping, fallback values, and print limitations.
Standard Draft standard Approximation Browser-dependent
Methodology Color difference: Delta E and OKLab distance How Hue Codex calculates Delta E 76 and OKLab distance, including the bounded OKLab objective used by Color Picker Repair 2.0.
Standard Hue Codex heuristic Approximation
Methodology Color-vision simulation model and limits How Hue Codex simulates common color-vision differences, evaluates pair risks, ranks hue-only collapse, and explains simulation limits.
Approximation Hue Codex heuristic
Methodology Image sampling, palette extraction, and duotone processing How Hue Codex samples pixels, extracts image palettes, handles transparent pixels, ranks image swatches, processes duotones, exports PNG files, and protects local image privacy.
Browser-dependent Approximation Hue Codex heuristic
Methodology Export formats, tokens, CSS variables, and fallbacks How Hue Codex formats semantic CSS, Tailwind v4 themes, JSON, DTCG 2025.10 color tokens and Resolver companions, SCSS, reports, and fallbacks.
Standard Draft standard Hue Codex heuristic Approximation Browser-dependent
Methodology Reference data sources and editorial policy How Hue Codex handles CSS named colors, glossary entries, editorial definitions, source notes, caveats, and review dates.
Standard Primary source Model source Hue Codex heuristic Approximation
Methodology Known limitations of Hue Codex color tools A consolidated, maintained register of Hue Codex calculation, browser, accessibility, image, gamut, export, and production limitations, with links to the detailed methodology for each area.
Hue Codex heuristic Approximation Browser-dependent

Coverage matrix

Which methodology pages explain each tool output.

This matrix follows the public Tools page order and uses the same methodology mapping shown on individual tool pages.

27 public tools mapped against 10 methodology pages.
Tool Contrast Conversion Palette Mixing Gamut Difference CVD Image Export Reference
Color Picker Tool group: Core tools Covered: Contrast methodology. Covered: Conversion methodology. Not applicable: Palette methodology. Not applicable: Mixing methodology. Not applicable: Gamut methodology. Not applicable: Difference methodology. Not applicable: CVD methodology. Covered: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
Color Converter Tool group: Core tools Not applicable: Contrast methodology. Covered: Conversion methodology. Not applicable: Palette methodology. Not applicable: Mixing methodology. Covered: Gamut methodology. Not applicable: Difference methodology. Not applicable: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
Contrast Checker Tool group: Core tools Covered: Contrast methodology. Covered: Conversion methodology. Not applicable: Palette methodology. Not applicable: Mixing methodology. Not applicable: Gamut methodology. Not applicable: Difference methodology. Not applicable: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
Palette Generator Tool group: Core tools Covered: Contrast methodology. Covered: Conversion methodology. Covered: Palette methodology. Not applicable: Mixing methodology. Not applicable: Gamut methodology. Not applicable: Difference methodology. Not applicable: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
CSS Color Generator Tool group: CSS tools Not applicable: Contrast methodology. Covered: Conversion methodology. Not applicable: Palette methodology. Not applicable: Mixing methodology. Covered: Gamut methodology. Not applicable: Difference methodology. Not applicable: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
CSS Gradient Generator Tool group: CSS tools Covered: Contrast methodology. Covered: Conversion methodology. Not applicable: Palette methodology. Covered: Mixing methodology. Not applicable: Gamut methodology. Not applicable: Difference methodology. Not applicable: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
Color Harmonies Tool group: Palette tools Covered: Contrast methodology. Covered: Conversion methodology. Covered: Palette methodology. Covered: Mixing methodology. Not applicable: Gamut methodology. Not applicable: Difference methodology. Not applicable: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
Tint, Shade, and Tone Generator Tool group: Palette tools Covered: Contrast methodology. Covered: Conversion methodology. Covered: Palette methodology. Covered: Mixing methodology. Not applicable: Gamut methodology. Not applicable: Difference methodology. Not applicable: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
Accessible Text Color Tool group: Palette tools Covered: Contrast methodology. Covered: Conversion methodology. Covered: Palette methodology. Not applicable: Mixing methodology. Not applicable: Gamut methodology. Not applicable: Difference methodology. Not applicable: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
CSS Named Colors Reference Tool group: Reference tools Covered: Contrast methodology. Covered: Conversion methodology. Not applicable: Palette methodology. Not applicable: Mixing methodology. Not applicable: Gamut methodology. Not applicable: Difference methodology. Not applicable: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Covered: Reference methodology.
Color Glossary Tool group: Reference tools Not applicable: Contrast methodology. Not applicable: Conversion methodology. Not applicable: Palette methodology. Not applicable: Mixing methodology. Not applicable: Gamut methodology. Not applicable: Difference methodology. Not applicable: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Covered: Reference methodology.
Color Model Comparison Tool group: Reference tools Not applicable: Contrast methodology. Covered: Conversion methodology. Not applicable: Palette methodology. Not applicable: Mixing methodology. Covered: Gamut methodology. Covered: Difference methodology. Not applicable: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
Gamut Checker Tool group: Reference tools Not applicable: Contrast methodology. Covered: Conversion methodology. Not applicable: Palette methodology. Not applicable: Mixing methodology. Covered: Gamut methodology. Not applicable: Difference methodology. Not applicable: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
Color Difference Calculator Tool group: Reference tools Not applicable: Contrast methodology. Covered: Conversion methodology. Not applicable: Palette methodology. Not applicable: Mixing methodology. Not applicable: Gamut methodology. Covered: Difference methodology. Not applicable: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
Color Mixer Tool group: Adjustment tools Not applicable: Contrast methodology. Covered: Conversion methodology. Not applicable: Palette methodology. Covered: Mixing methodology. Not applicable: Gamut methodology. Covered: Difference methodology. Not applicable: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
Opacity Calculator Tool group: Adjustment tools Covered: Contrast methodology. Covered: Conversion methodology. Not applicable: Palette methodology. Covered: Mixing methodology. Not applicable: Gamut methodology. Not applicable: Difference methodology. Not applicable: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
Color Temperature Adjuster Tool group: Adjustment tools Not applicable: Contrast methodology. Covered: Conversion methodology. Covered: Palette methodology. Covered: Mixing methodology. Covered: Gamut methodology. Covered: Difference methodology. Not applicable: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
Saturation and Chroma Adjuster Tool group: Adjustment tools Not applicable: Contrast methodology. Covered: Conversion methodology. Covered: Palette methodology. Not applicable: Mixing methodology. Covered: Gamut methodology. Covered: Difference methodology. Not applicable: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
Lightness Ladder Generator Tool group: Adjustment tools Covered: Contrast methodology. Covered: Conversion methodology. Covered: Palette methodology. Covered: Mixing methodology. Not applicable: Gamut methodology. Covered: Difference methodology. Not applicable: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
Gradient Palette Extractor Tool group: Adjustment tools Covered: Contrast methodology. Covered: Conversion methodology. Covered: Palette methodology. Covered: Mixing methodology. Not applicable: Gamut methodology. Covered: Difference methodology. Not applicable: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
Color Blindness Simulator Tool group: Accessibility tools Covered: Contrast methodology. Covered: Conversion methodology. Not applicable: Palette methodology. Not applicable: Mixing methodology. Not applicable: Gamut methodology. Covered: Difference methodology. Covered: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
Accessible Pair Finder Tool group: Accessibility tools Covered: Contrast methodology. Covered: Conversion methodology. Covered: Palette methodology. Not applicable: Mixing methodology. Not applicable: Gamut methodology. Not applicable: Difference methodology. Covered: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
Focus Ring Contrast Tool Tool group: Accessibility tools Covered: Contrast methodology. Covered: Conversion methodology. Not applicable: Palette methodology. Not applicable: Mixing methodology. Not applicable: Gamut methodology. Not applicable: Difference methodology. Not applicable: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
Link Color Checker Tool group: Accessibility tools Covered: Contrast methodology. Covered: Conversion methodology. Not applicable: Palette methodology. Not applicable: Mixing methodology. Not applicable: Gamut methodology. Not applicable: Difference methodology. Covered: CVD methodology. Not applicable: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
Image Eyedropper Tool group: Image tools Covered: Contrast methodology. Covered: Conversion methodology. Not applicable: Palette methodology. Not applicable: Mixing methodology. Not applicable: Gamut methodology. Not applicable: Difference methodology. Not applicable: CVD methodology. Covered: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
Image Palette Extractor Tool group: Image tools Covered: Contrast methodology. Covered: Conversion methodology. Covered: Palette methodology. Not applicable: Mixing methodology. Not applicable: Gamut methodology. Covered: Difference methodology. Covered: CVD methodology. Covered: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.
Duotone Generator Tool group: Image tools Covered: Contrast methodology. Covered: Conversion methodology. Not applicable: Palette methodology. Covered: Mixing methodology. Covered: Gamut methodology. Covered: Difference methodology. Not applicable: CVD methodology. Covered: Image methodology. Covered: Export methodology. Not applicable: Reference methodology.