Skip to content

Chart Color System

by socraticstatic · remote · no sign-in to list tools · v0.1.2 · published by GitHub user socraticstatic

Solve, audit and simulate colorblind-safe chart palettes. WCAG contrast, OKLab ΔE. Read-only.

Changes · 3

4 tools: 3 change things and 1 only read.

Scanned Oct 21, 2026

1 check matched something in the tool definitions. No finding is not a safety guarantee. How the checks work.

claude mcp add --transport http chart-color-system https://chart-color-mcp.vercel.app/mcp

Findings

Matches of fixed checks, with the text they matched.

1 warn
  • The server marks "solve_palette" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

    Matched text

    annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":false}; The description's first verb is "generate": a word for a change.

    What this check looks for

Tools

Open a tool for its reasons and full description. Descriptions are the publisher's own words, shown as they are.

4 tools

Changes things 3Claude Code: ask
  • audit_paletteAudit existing chart colors for accessibility: pairwise OKLab separation under normal vision, deuteranopia, protanopia, tritanopia and achromatopsia, plus WCAG 2.2 non-text contras…No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Audit existing chart colors for accessibility: pairwise OKLab separation under normal vision, deuteranopia, protanopia, tritanopia and achromatopsia, plus WCAG 2.2 non-text contrast (3:1) of every color against the chart background. Returns a pass / warn / fail verdict with the numbers behind it. Set ramp=true for sequential or diverging scales, whose steps are meant to be close.

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • build_rampBuild an evenly spaced perceptual (OKLab) color scale: sequential from start to end, or diverging from start through mid to end.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Build an evenly spaced perceptual (OKLab) color scale: sequential from start to end, or diverging from start through mid to end. Returns the steps and a background-contrast audit (pairwise separation is not judged for ramps).

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • solve_paletteGenerate a categorical chart palette of n colors (1-12) that maximizes perceptual separation under normal vision and colorblindness, with the given brand colors locked as anchors i…1 finding

    Why it is in this group

    • The description's first verb is "generate": a word for a change.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.

    Findings

    • Warn

      The server marks "solve_palette" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

      Matched text

      annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":false}; The description's first verb is "generate": a word for a change.

      What this check looks for
    Description, as the server wrote it
    Generate a categorical chart palette of n colors (1-12) that maximizes perceptual separation under normal vision and colorblindness, with the given brand colors locked as anchors in slot order. Returns the palette, the worst pair distances, the engine's relaxation notes, a full accessibility audit against the background, and a link to open it in the app. Honest cap is 6 slots; above that the result says so.

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
Only reads 1Claude Code: allow
  • simulate_paletteShow what each color looks like to readers with deuteranopia, protanopia, tritanopia or achromatopsia (published Machado 2009 matrices), so an assistant can describe or render the …No findings

    Why it is in this group

    • The description's first verb is "show": a word for reading.
    Description, as the server wrote it
    Show what each color looks like to readers with deuteranopia, protanopia, tritanopia or achromatopsia (published Machado 2009 matrices), so an assistant can describe or render the palette as a colorblind reader sees it.

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false

This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.

Install

Pinned to version 0.1.2. Values in angle brackets are yours to fill in.

claude mcp add --transport http chart-color-system https://chart-color-mcp.vercel.app/mcp

Run in a terminal.

Claude Code permissions

Allow the reads, ask before a change, deny the deletes. Paste into .claude/settings.json.

.claude/settings.json
{
  "permissions": {
    "allow": [
      "mcp__chart-color-system__simulate_palette"
    ],
    "ask": [
      "mcp__chart-color-system__solve_palette",
      "mcp__chart-color-system__audit_palette",
      "mcp__chart-color-system__build_ramp"
    ],
    "deny": []
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. It assumes the server is installed as chart-color-system. Review it before you use it.