# adobe/leonardo

Generate colors based on a desired contrast ratio

Repository: https://github.com/adobe/leonardo
Canonical: https://ross.abutalabs.com/products/leonardo
Homepage: http://www.leonardocolor.io
Language: JavaScript
License: Apache-2.0
License Family: permissive
Topics: contrast-ratio, a11y, contrast, color, colors, colorscheme, colorscheme-generator, color-picker, color-theme, color-themes, dark, color-generator, color-palette, color-palette-generator, color-theme-switcher
Last push: 2026-07-08T22:10:56+00:00

## Health v2 (maintenance only)
Score: 86/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 91, release rhythm 71, longevity 100
- inputs: {"age_days": 2508, "days_push": 56, "days_rel": 194, "gap_med": 1.0, "n_releases_24m": 3}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2136, forks 130 (observed 2026-08-28T04:06:17.602080+00:00)

## What it is
Leonardo is an open-source tool from Adobe for generating accessible, adaptive color palettes based on desired contrast ratios. It includes an npm library (@adobe/leonardo-contrast-colors) and a web application for building color scales for UI design systems and data visualization.

## Use cases
- generate color palettes that meet WCAG contrast requirements
- create accessible dark mode color themes
- build perceptually uniform color scales for data visualization
- generate colorblind-safe palettes
- create adaptive color themes with adjustable contrast and brightness
- export design tokens and CSS custom properties for color systems

## When to choose
- you need colors that conform to WCAG contrast standards by design rather than post-hoc auditing
- you're building a design system with light and dark adaptive themes
- you need sequential or diverging color scales for data visualization
- you want to let end users personalize contrast, brightness, or saturation

## When to avoid
- you just need a quick color picker without accessibility constraints
- your project doesn't involve UI color theming or data visualization
- you need a non-JavaScript environment without npm support

## Facets
- artifact type: library
- maturity: active
- function: ui-components, theme, accessibility, data-visualization
- domain: web-design, frontend, accessibility
- platform: browser, cross-platform
- tags: color-science, color-palette-generator, wcag-contrast, adaptive-theming, dark-mode, design-tokens, colorblind-safe, design-systems, nodejs, web-server

## Member repositories
- adobe/leonardo (main) score 86

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:17.602080+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T02:51:51.906525+00:00, confidence not recorded.
  - readme: https://github.com/adobe/leonardo (fetched 2026-08-28T04:06:17.602080+00:00, sha 02337c7ba6e0)
  - homepage: http://www.leonardocolor.io (fetched 2026-08-29T10:32:10.779163+00:00, sha 29cbe9260951)
- Data as of 2026-08-30T08:39:29.467469+00:00.