# Color Blindness Palette Simulator

> Simulate protan, deutan and tritan vision for a palette and find colors that become confusable. Paste 2–24 colors and simulate protanomaly, deuteranomaly and tritanomaly from mild to full dichromacy with the Machado, Oliveira and Fernandes (2009) model. Pairs whose simulated CIEDE2000 difference falls below your threshold are listed, so you can fix chart, map and UI palettes before anyone squints.

Part of usefulweb.app (https://usefulweb.app/). Part of [Lumina](https://lumina.usefulweb.app/) (ownerApp: lumina). Results are deterministic calculations from the inputs and the listed assumptions; the API returns exactly what the web page shows.

## Use it
- Human interface: https://luminacvdsimulator.usefulweb.app/ (interactive tool at https://luminacvdsimulator.usefulweb.app/tool)
- JSON API: POST https://luminacvdsimulator.usefulweb.app/api/v1/calculate with a JSON object of inputs (schema: https://luminacvdsimulator.usefulweb.app/api/v1/tool)
- OpenAPI: https://luminacvdsimulator.usefulweb.app/openapi.json
- MCP (Streamable HTTP): https://luminacvdsimulator.usefulweb.app/mcp - tool `lumina_cvd_simulator`

## Inputs
- colors (textarea): Palette colors (HEX or CSS colors, one per line or separated by spaces)
- type (select): Color-vision type
- severity (integer): Severity (%; 100 = dichromacy)
- threshold (number): Confusion threshold (ΔE2000)

## Method
- Each color is gamut-mapped to 8-bit sRGB, decoded to linear light and multiplied by the Machado, Oliveira and Fernandes (2009) simulation matrix. The published matrices cover severities 0–100% in 10% steps; other severities interpolate linearly between the two nearest matrices, as the authors suggest. 100% simulates dichromacy.
- For normal vision and each simulated type, every pair is compared with CIEDE2000 in CSS Lab (D50). Pairs below the threshold are reported as confusable, together with their normal-vision difference; pairs that are already too close in normal vision are listed once, under normal vision.
- The threshold is a design heuristic, not a standard: around 10 suits small chart marks and thin lines, larger areas tolerate less. Individual color vision varies; the simulation is an approximation and does not certify accessibility. Do not rely on color alone — add labels, patterns or shapes.