Colors LE

---

Useful? A star or rating is how other developers find it — ★ GitHub · ★ Open VSX · ★ Marketplace

What it does

Open a file, press Ctrl+Alt+C (Cmd+Alt+C on Mac), and every color in the document lands in a new editor — deduplicate, sort, convert, filter, analyze, or validate it from there. Works in VS Code and in VS Code–based editors like Cursor and VSCodium (installable from Open VSX).

• Palette auditing — every hex, rgb()/rgba(), hsl()/hsla(), and named color in stylesheets, markup, and code
• Design-system review — analyze distribution, cluster similar colors, spot near-duplicates
• Accessibility checks — contrast ratios against WCAG AA/AAA via the Validate command

Install

Where	What you get	Install
VS Code	Extraction, conversion, analysis and validation in your editor	Marketplace
Cursor, VSCodium, Windsurf	The same extension	Open VSX
A terminal or a CI step	The same extraction over a whole tree, with exit codes	cargo install colors-le · crates.io
Any MCP agent, via Node	extract_colors over stdio	npx colors-le-mcp · npm
Zed	The MCP server as a context server	zed-industries/extensions#7078 (pending review)

Use it from an AI agent

The same engine runs as an MCP server, so an agent can call it directly instead of you running a command.

Editor	How
VS Code 1.101+	Nothing to install — the extension registers extract_colors with agent mode
Zed	Colors-LE — pending review
Claude Code	claude mcp add colors-le -- npx -y colors-le-mcp
Cursor, Windsurf, anything else	point it at npx colors-le-mcp

extract_colors(content, format?, filename?, dedupe?, maxResults?)

Returns every color with its notation and 1-based line and column, capped at 500 by default with meta.truncated so a large stylesheet cannot flood the agent's context window.

The server takes content and returns data — it reads no files and makes no network requests of its own. Published as colors-le-mcp on npm and as io.github.nolindnaidoo/colors-le in the MCP registry.

Most hosts read a JSON config. Add one entry:

{
  "mcpServers": {
    "colors-le": {
      "command": "npx",
      "args": ["-y", "colors-le-mcp"]
    }
  }
}

-y skips the install prompt on first run. Pin a version if you would rather not track releases — colors-le-mcp@2.3.1.

Prefer not to go through npx on every launch? Install it once and point at the binary instead:

npm install -g colors-le-mcp

{
  "mcpServers": {
    "colors-le": { "command": "colors-le-mcp" }
  }
}

It speaks MCP over stdio and needs no environment variables, no API key and no configuration of its own. To check it before wiring it into anything:

echo '{"jsonrpc":"2.0","id":1,"method":"tools/list"}' | npx -y colors-le-mcp

That prints the tool list and exits — if you see extract_colors, the server works.

Supported formats

Format	Language IDs	Where colors are recognized
CSS	css	Hex/functional literals anywhere outside comments; named colors in declaration values
SCSS / LESS / Stylus	scss, less, stylus	Same as CSS, plus // line comments respected; Stylus = assignments count as values
HTML	html	style="…" attributes, <style> blocks, color/bgcolor attributes
JavaScript / TypeScript	javascript, javascriptreact, typescript, typescriptreact	Inside string and template literals (theme objects, styled-components); named colors only when the whole string is the color
SVG / XML	xml, svg	fill, stroke, stop-color, flood-color, lighting-color, color, bgcolor attributes, plus style attributes/blocks
JSON / YAML / TOML	json, jsonc, yaml, toml	Design tokens: literals anywhere, named colors where the value is the color
Markdown / plain text	markdown, plaintext	Same, and a 3- or 4-digit hex must contain an a-f — #250 in prose is an issue reference
Everything else	any language id	Read as raw text under the same rules, and reported as unknown

No document is refused. A language with no reader of its own is read as raw text, and metadata.fileType says which of the two answered.

Recognized syntax: #rgb, #rgba, #rrggbb, #rrggbbaa, comma-form rgb()/rgba()/hsl()/hsla() (calls may span multiple lines), and the CSS named colors including rebeccapurple and transparent. Positions are real 1-based line/column of each literal. Comments never produce colors, and comment markers inside strings don't start comments.

Known limitations (documented, not bugs): modern space-separated syntax (rgb(255 0 0 / 50%)) and lab()/lch()/oklch()/color() are not extracted; a hex inside any JS string matches, including URL fragments; Stylus values without : or = only yield hex/functional literals, not named colors; in the raw-text scan a value segment runs to the end of the line, so two tokens on one line cost the named one.

The CLI

The same extraction from a terminal or a CI step — a Rust CLI in crate/, installed with cargo install colors-le. Convert, analyze and validate are interactive and stay in the editor.

colors-le .                              # every colour in the tree
colors-le --palette brand.txt .          # what is not in the palette
colors-le --values --dedupe . | sort -u  # write the palette in the first place
colors-le mcp                            # the same extraction over MCP on stdio

Exit codes: 0 clean, 1 none found or a colour outside the palette, 2 the question was malformed.

Matched by colour, not by spelling. A palette written in hex still catches a violation written in rgb(), because #FFF, #ffffff and rgb(255, 255, 255) are one entry. Alpha is part of the identity, and a named colour is only equal to itself — white and #ffffff are the same pixel and not the same decision.

Commands

Command	Description
Colors-LE: Extract Colors (Ctrl+Alt+C / Cmd+Alt+C)	Extract all colors from the active document
Colors-LE: Analyze Colors	Statistics, clusters, patterns, and palette report
Colors-LE: Convert Colors	Convert extracted colors to hex/rgb/hsl
Colors-LE: Filter Colors	Filter by format, lightness, saturation
Colors-LE: Validate Colors	Format validation and WCAG contrast checks
Colors-LE: Deduplicate Colors	Remove duplicate lines from the results
Colors-LE: Sort Colors	Sort results by the configured sortMode
Colors-LE: Open Settings	Open Colors-LE settings
Colors-LE: Help	Built-in documentation

Settings

Setting	Default	Description
colors-le.openResultsSideBySide	true	Open results beside the current editor (off = replace in place)
colors-le.copyToClipboardEnabled	false	Also copy results to the clipboard
colors-le.dedupeEnabled	false	Deduplicate extraction results automatically
colors-le.sortMode	off	Sort order used by the Sort command (hue/saturation/lightness/hex, asc/desc)
colors-le.notificationsLevel	silent	all = every notification, important = warnings + errors, silent = errors only
colors-le.safety.enabled	true	Guardrails for very large files
colors-le.safety.fileSizeWarnBytes	1000000	Refuse extraction above this file size (override prompt offered)
colors-le.safety.largeOutputLinesThreshold	50000	Warn above this line count
colors-le.statusBar.enabled	true	Show the status bar item
colors-le.telemetryEnabled	false	Local-only event log (see Privacy)

Languages

Twelve languages besides English:

German · Spanish · French · Indonesian · Italian · Japanese · Korean · Portuguese (Brazil) · Russian · Ukrainian · Vietnamese · Chinese (Simplified)

Both halves are covered — the manifest (command titles, setting names and descriptions) and everything shown while the extension runs (notifications, the status bar, quick-picks and prompts). The extension follows VS Code's display language, so it matches whatever the editor is already set to; no setting of its own.

Privacy & security

• No network access. The extension never sends data anywhere. The telemetryEnabled setting only writes events to a local Output Channel you can inspect (Colors-LE Telemetry).
• The MCP server holds the same line. It takes content as an argument and returns data: no filesystem access, no network calls, no telemetry. Your agent already has file-read tools, so duplicating them inside the server would add a path-traversal surface for no capability. check:mcp-bundle fails the build if the server ever imports something that could reach either.
• Error notifications redact home directories and credential-shaped fragments.

Documentation

What	Where
What the tool is allowed to say — extraction scope, output contract, refusals, non-goals	crate/SPEC.md
How the extension is built and held together — architecture, invariants, toolchain, release	AGENTS.md
How the CLI is built and held together	crate/AGENTS.md
What changed	CHANGELOG.md · crate/CHANGELOG.md
The tool's page, and the other fifteen	letools.dev/tools/colors-le

Performance

Input	Size	Found	Time	Rate	Scan speed
CSS stylesheet	1.58 MB	60,000	57.25 ms	1,048,075/sec	27.7 MB/s
SCSS variables	1.96 MB	60,000	67.02 ms	895,249/sec	29.3 MB/s
HTML markup	1.29 MB	50,000	33.72 ms	1,482,680/sec	38.2 MB/s

Median of 7 runs after warmup, on Apple M5 Pro, 24 GB RAM, Node 24.3.0. Inputs are generated by scripts/benchmark.ts rather than checked in, so the sizes above are exactly what was measured. Reproduce with bun run benchmark.

These are machine-specific and are not asserted in CI — a benchmark that gates a build only tells you how busy the runner was.

Testing

Metric	Coverage
Statements	90.79%
Branches	79.43%
Functions	95.48%
Lines	92.13%

347 test cases across 24 files, plus an integration suite that runs in a real VS Code extension host and an end-to-end test that installs the built .vsix into a clean profile.

Generated from a real run — coverage/coverage-summary.json and coverage/test-results.json — by scripts/coverage-readme.js; CI fails if this section drifts. Reproduce with bun run test:coverage, and the case count is the one vitest prints.

More from the LE family

Sixteen single-purpose tools for the work in front of every model. Each ships a Rust CLI and an MCP server. One page: letools.dev

Get it out

• String-LE — Extract every string in a codebase, with its position, so a person can read them
• Numbers-LE — Extract every hardcoded number in a codebase, so a person can check them
• Units-LE — Extract every quantity with its unit, normalized, and refuse the ambiguous ones by name
• Dates-LE — Extract every date and timestamp, and the exact instant each one resolves to
• IDs-LE — Extract every UUID, ULID, NanoID, ObjectId and Snowflake, and decode the time inside
• IPs-LE — Extract every IP address, CIDR block and MAC, normalized and classified by scope
• URLs-LE — Extract every URL in a codebase, with its protocol and exact position
• Paths-LE — Extract every file path in a codebase, and say whether it still points at anything
• Colors-LE — Extract every color in a codebase, and say which ones are not in your palette

Check it

• Regex-LE — Find every regex in a codebase, and report which can be driven into catastrophic backtracking
• Versions-LE — Find where one dependency is constrained differently across a repository's manifests
• i18n-LE — Identify the i18n library a project uses, then audit its catalogs by that library's rules
• Scrape-LE — Check whether a page is scrapeable before the scraper is written, and say when it cannot tell

Guard it

• Secrets-LE — Find hardcoded credentials in a codebase, and never print one into the report
• EnvSync-LE — Compare the dotenv files in a tree, and say which keys are missing from which
• Unicode-LE — Find the Unicode that hides meaning — bidi controls, invisibles, homoglyphs, mixed scripts

Each stands on its own: no shared crate, no published core. Where two of them agree, it is because the same answer was right twice.

Contact — nolindnaidoo.com · GitHub · LinkedIn

Also by nolindnaidoo

Rust — pixelcoords and pixelactions are one loop: pixelcoords answers where, pixelactions acts there. Their own tools, their own voice — not part of the LE family.

• pixelcoords — Freeze your screen, mark regions, get pixel-exact coordinates and crops pixelcoords.dev · crates.io · docs.rs
• pixelactions — Consume human-verified coordinates, perform the interaction, confirm it landed pixelactions.dev · crates.io · docs.rs

License

MIT © nolindnaidoo