API & MCP

Everything a person can do on Delta E Color Difference (CIEDE2000), a program or AI agent can do with the same inputs and get the identical result.

HTTP API

POST https://luminacolordifference.usefulweb.app/api/v1/calculate – run Delta E Color Difference (CIEDE2000)
GET https://luminacolordifference.usefulweb.app/api/v1/tool – inputs, output schema, examples
OpenAPI 3.1: /openapi.json · /openapi.yaml
Errors: application/problem+json; 422 includes per-field errors.

Delta E Color Difference (CIEDE2000)

Compare a reference color with up to 50 samples written as HEX, CSS names or any CSS color function, including lab(). Each row shows ΔE2000, ΔE94, ΔE76 and the OKLab distance, plus pass or fail against your tolerance, with a CSV report.

Inputs of Delta E Color Difference (CIEDE2000)
Field	Type	Default	Description
`reference`	text	"#164E63"	Reference color (CSS color)
`samples`	textarea	"#1A5A6F\n#164E64\nlab(30 -12 -20)"	Sample colors (one per line)
`method`	select (2000, 94, 76, ok)	"2000"	Tolerance method
`tolerance`	number	2	Pass tolerance (ΔE)

Example request

Three samples against a teal reference

curl -X POST https://luminacolordifference.usefulweb.app/api/v1/calculate -H 'content-type: application/json' -d '{"reference":"#164E63","samples":"#1A5A6F\n#164E64\nlab(30 -12 -20)","method":"2000","tolerance":2}'

Every result contains

inputs (normalised, defaults applied), summary, result (validated against the published schema), units, assumptions, sources, warnings, computedAt and links.

MCP (Model Context Protocol)

Streamable HTTP endpoint: https://luminacolordifference.usefulweb.app/mcp – protocol revisions 2026-07-28 (stateless) and 2025-11-25 / 2025-06-18 / 2025-03-26 (initialize handshake).
Tools: lumina_color_difference
Local stdio connector: node src/mcp-stdio.ts --tool=lumina-color-difference

{
  "mcpServers": {
    "lumina-color-difference": { "type": "http", "url": "https://luminacolordifference.usefulweb.app/mcp" }
  }
}