Open-Source Licenses and Plate Provenance

This site is built on open-source work, and every plate you can see traces back to a licensed, checksummed source. This page lists those projects, their licenses, and what we ship in return.

Color Vision Plates (MIT)

The fourteen core plate definitions — the control plate, the five general red-green designs, the protan- and deutan-directed experimental pairs, and the four blue-yellow designs — come from lukeslp/color-vision-plates by Luke Steuber, MIT licensed (© 2026), pinned to commit d49a641. We ported the plate definitions (CIELAB color specifications, seeds, answers, design groups) and the rendering pipeline (seeded PRNG, LAB→sRGB conversion, Poisson-disk dot placement) into this site, preserving the license file and the upstream's third-party notices. The upstream project's own disclaimer — the plates are not clinically validated — is carried through verbatim in spirit: our result pages never diagnose.

• License file: LICENSES/color-vision-plates.LICENSE
• Third-party notices: LICENSES/color-vision-plates.THIRD_PARTY_NOTICES.md

ishihara, Python package (MIT)

The nine digit plates on the Ishihara pages are generated by ishihara on PyPI (© 2026 Vincent Gonzalez, MIT license, version 0.1.2). Plates are generated at build time from fixed seeds and committed as SVG assets; each file's SHA-256 is recorded in the provenance ledger, so regenerating must reproduce byte-identical output. We publish the generator's parameters (figure, axis, seed) for all nine plates — check the methodology page for the pipeline.

• License file: LICENSES/ishihara.LICENSE

dichroma (MIT)

The color-vision simulation used by the simulator and the reverse-plate experiment is vendored from didrod205/dichroma (MIT license, © 2026 dichroma contributors, commit b8cd414). It implements the published Machado, Oliveira & Fernandes (2009) simulation matrices in linear RGB. The vendored copy keeps the upstream attribution header; the simulation is used for demonstration, never as a scorer.

• License file: LICENSES/dichroma.LICENSE

What we do NOT use

For clarity, because it matters legally and ethically: this site contains no scans, copies, or derivatives of the copyrighted printed Ishihara test booklets (the 24- or 38-plate clinical editions), no HRR plates, and no images taken from other test websites. All digit plates are generated original artwork from the open-source generator above. "Ishihara-style" on our pages describes the pseudoisochromatic principle, not the licensed clinical product.

The provenance ledger

data/plate-provenance.json in the site repository records every plate: identifier, bank, source project and URL, version or commit, license file, design group, expected answer, seed, asset path and SHA-256 where an asset file exists, and two fixed flags — clinicalValidation: false and qaApproved — for all 31 plates (14 core, 8 kids shapes, 9 Ishihara digits). The ledger is generated by a build script, never edited by hand; if a checksum changes, the version changes with it.

This site's own content

The page copy, page designs, the kids shape-plate color specifications and the heart figure are original to this site. The MIT license texts above cover the vendored components; everything else © 2026 Color Blindness Test. The site text is served for public reading and quoting with attribution; the plate pipeline remains reproducible per the methodology page.

Attribution summary

| Component | Author | License | Used for | | ------------------- | --------------------- | ------- | ---------------------------------------------- | | color-vision-plates | Luke Steuber | MIT | 14 core plate definitions + rendering math | | ishihara (PyPI) | Vincent Gonzalez | MIT | 9 digit plate SVGs | | dichroma | dichroma contributors | MIT | CVD simulation (simulator, reverse experiment) |

If you believe any attribution is missing or incorrect, the contact page explains how to tell us — we fix licensing issues immediately.