Known limitations of Hue Codex color tools

Representative automated fixture coverage

Hue Codex imports versioned JSON fixtures and tests the corresponding pure production functions directly. The groups below are the representative regression evidence most relevant to this methodology.

• Parsing fixtures: Accepted CSS color syntax, alpha behavior, clamping, invalid input, and out-of-gamut fallback cases. View the JSON fixtures.
• Contrast fixtures: Known ratios, threshold boundaries, symmetry, and unrounded pass/fail behavior. View the JSON fixtures.
• Conversion fixtures: sRGB, XYZ, Lab/LCH, OKLab/OKLCH conversion values, round trips, and precision boundaries. View the JSON fixtures.
• Palette fixtures: Deterministic role output, locked-color preservation, readable-pair metadata, and export consistency. View the JSON fixtures.
• Export fixtures: Displayed-versus-exported values, parseable CSS and JSON, and safe allowlisted SVG output. View the JSON fixtures.
• Image-sampling fixtures: Known RGBA pixel grids, coordinate bounds, alpha handling, averages, and deterministic samples. View the JSON fixtures.

What a pass means. A passing group confirms the named vectors and tested properties still match the documented implementation. It does not prove every possible input, final browser rendering, full accessibility conformance, profile-aware print output, or every downstream export consumer.

The color-math suite imports versioned JSON fixtures and exercises pure production functions for parsing, conversion, contrast, palette behavior, exports, and image sampling. Property checks cover invariants such as round trips, contrast symmetry, locked-color preservation, parseable exports, and safe SVG output.

A green fixture group is regression evidence for its documented vectors and properties. It is not statistical proof over every possible input, a substitute for browser testing, or a certification of a final design, accessibility conformance, color-managed print output, or every consumer that may parse an export.

Evidence boundary. Hue Codex should describe fixture results as representative, deterministic regression checks, never as proof that no defect can exist.

• Verify final foreground/background pairs, text sizes, component states, focus indicators, labels, keyboard behavior, and non-color cues in the actual interface.
• Test modern color syntax, gradients, downloads, clipboard behavior, fonts, and forced-colors behavior in the browsers and devices the product supports.
• Review out-of-gamut authored values and any sRGB fallback separately so clipping is not mistaken for perceptual gamut mapping.
• Use profile-aware workflows, proofs, substrate and ink details, and vendor requirements for print-critical work.
• Inspect real images at relevant sizes and quality settings; browser canvas output and sampled palettes are not substitutes for source-profile analysis.
• Validate exported CSS, JSON, SVG, and token data in the actual downstream build system or consumer, including naming and support requirements.

These limitations are maintained with the subject methodology so caveats stay beside the formulas, assumptions, validation examples, and source status they qualify.

• Contrast alone does not prove accessibility or usability.
• Anti-aliasing, thin type, images, texture, gradients, and final component placement can change real readability.
• Anti-aliased or smoothed text can appear lower contrast than the nominal CSS/source color pair, especially with thin or unusual fonts.
• Focus Ring Contrast checks adjacent-color contrast only; it does not validate the full WCAG 2.2 Focus Appearance size, area, or state-change requirements.
• Disabled controls, logos, incidental text, and decorative content can have WCAG exceptions that require judgment.

These limitations are maintained with the subject methodology so caveats stay beside the formulas, assumptions, validation examples, and source status they qualify.

• Converting an out-of-gamut perceptual color back to sRGB can clamp channels and hide lost chroma.
• Clamped fallback values should not be used as proof that an out-of-gamut authored color has been perceptually mapped into sRGB.
• Once a zero-chroma or achromatic authored color has resolved to sRGB, downstream tools cannot infer a meaningful original hue from it.
• Browser rendering, color management, and unsupported notation can change what users actually see.
• CSS Color 5 references are draft context and should not be treated as final standards authority.

These limitations are maintained with the subject methodology so caveats stay beside the formulas, assumptions, validation examples, and source status they qualify.

• Generated palettes are starting points and do not guarantee a complete brand or product color system.
• High-chroma or very neutral seeds can produce constrained, clipped, or low-chroma companions.
• Final UI roles still need component-level contrast, color-vision, and state review.
• A random seed cannot be regenerated from an internal PRNG seed because Hue Codex does not expose or store a seeded PRNG state.

These limitations are maintained with the subject methodology so caveats stay beside the formulas, assumptions, validation examples, and source status they qualify.

• CSS Color 5 color-mix() and related modern interpolation features are draft-standard context.
• Hue Codex does not parse an arbitrary color-mix() expression as input or generate forms with omitted percentages, more than two colors, currentColor, contextual colors, or leftover percentage alpha.
• Internal component interpolation uses each endpoint’s resolved sRGB fallback channels, so an authored out-of-sRGB endpoint may differ from a color-managed browser interpolation of its original wide-gamut syntax.
• Sampled gradient contrast does not test every pixel or every final text position.
• Encoded sRGB mixes differ from linear-light sRGB mixes; Hue Codex labels the mode so users can choose the interpolation model intentionally.
• Encoded sRGB opacity compositing can differ from linear-light or color-managed rendering pipelines; Hue Codex reports the resolved fallback it calculates rather than claiming to reproduce every renderer.
• Achromatic HSL inputs have powerless hue; Hue Codex currently carries the derived numeric fallback hue 0 through HSL interpolation rather than preserving an authored missing-hue marker.
• Browser support and rendering differ across gradient syntax, interpolation spaces, and wide-gamut output.

These limitations are maintained with the subject methodology so caveats stay beside the formulas, assumptions, validation examples, and source status they qualify.

• CMYK output is approximate and not press-ready.
• CSS Color 5 device-cmyk(), @color-profile, and custom color spaces are draft-standard context, and W3C currently marks those features as at-risk.
• The Gamut Checker handles its documented concrete CSS spaces, but it does not accept arbitrary custom profiles, device-cmyk(), Rec. 2020 input syntax, ICC-profile colors, or contextual CSS expressions.
• Real print conversion needs ICC profiles, total ink limits, paper, ink, press condition, proofs, and vendor guidance.

These limitations are maintained with the subject methodology so caveats stay beside the formulas, assumptions, validation examples, and source status they qualify.

• Delta E 76 is simple and explainable but not uniformly perceptual in every color region.
• Delta E 2000 is more suitable for color-critical tolerance work, but Hue Codex does not currently calculate it.
• A high color-difference score does not mean text is readable.
• Viewing conditions, display calibration, materials, and adaptation can change perceived difference.

These limitations are maintained with the subject methodology so caveats stay beside the formulas, assumptions, validation examples, and source status they qualify.

• Simulation is approximate and represents full-condition screening views, not anomalous trichromacy, partial severity, or individual color-vision profiles.
• The model does not account for display calibration, viewing distance, lighting, eye conditions, or adaptation.
• WCAG contrast conformance is based on the actual rendered foreground and background colors, not on a simulated perception transform.
• Passing simulation checks does not prove accessibility; meaning still needs labels, shape, position, and context.

These limitations are maintained with the subject methodology so caveats stay beside the formulas, assumptions, validation examples, and source status they qualify.

• Canvas pixels, image decoding, color management, and cross-origin rules are browser-dependent.
• Hue Codex samples the browser-converted canvas pixel buffer, not original embedded ICC profile values, raw Display P3 pixels, or a profile-aware color-managed source representation.
• Hue Codex does not parse EXIF orientation itself; source coordinates refer to the browser-decoded image orientation and canvas draw result.
• Extracted image palettes are starting-point palettes for design review, not finished production color systems.
• Palette extraction is approximate and depends on sampling quality, compression artifacts, and image content.
• CSS duotone output is an approximation and may not match exported PNG pixels.

These limitations are maintained with the subject methodology so caveats stay beside the formulas, assumptions, validation examples, and source status they qualify.

• The Design Tokens Format Module 2025.10 is a stable DTCG Community Group specification intended for implementation, but it is not a W3C Recommendation; Hue Codex token-style exports do not currently claim conformance.
• CSS Color 5 functions such as color-mix(), light-dark(), and device-cmyk() are draft-standard context.
• Clipboard and downloaded files depend on browser behavior and the current tool state.

These limitations are maintained with the subject methodology so caveats stay beside the formulas, assumptions, validation examples, and source status they qualify.

• Reference data is educational and does not replace the underlying standard, specification, or production requirement.
• Subjective color meaning should not be presented as universal across cultures, industries, products, or users.
• Draft or approximate topics must be called out when they appear in reference copy.

Report a calculation issue

If a result does not match the documented formula or fixture, send the exact input, tool settings, displayed result, expected result, precision mode, and browser details. Please do not include private images, personal information, or secrets.