# Chart Color System

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

- name: io.github.socraticstatic/chart-color-system
- version: 0.1.2
- connection class: R0 (autonomous)
- trust: 97/100
- quality: 91/100 (strong)
- owner: not claimed
- descriptor: https://api.protogrid.dev/v1/servers/io.github.socraticstatic%2Fchart-color-system
- tools: https://api.protogrid.dev/v1/servers/io.github.socraticstatic%2Fchart-color-system/tools

**An agent can connect right now, no human step.** Remote endpoint, no authentication, reachable on the last probe.

## Connection (mcpServers)

```json
{
  "mcpServers": {
    "chart-color-system": {
      "type": "http",
      "url": "https://chart-color-mcp.vercel.app/mcp"
    }
  }
}
```


## Trust

- hygiene: 100
- liveness: 100
- freshness: 100
- provenance: 90
- drivers: +repository +namespace-matches-repo +website +reachable +uptime-100% +updated-16d-ago
- Derived from observable signals (official registry feed and our own credential-free probes); no code audit performed.

## Quality 91/100 (strong)

### protocol: 75 (weight 25)

- warn `protocol.modern`: newest supported version is 2025-11-25; 2026-07-28 not supported, older versions are deprecated until 2027-07-28
- n/a `protocol.stateless`: only applies to 2026-07-28 servers
- pass `protocol.transport`: streamable HTTP
- n/a `protocol.list_ttl`: only applies to 2026-07-28 servers

### authorization: n/a (weight 15)

- n/a `auth.prm`, `auth.as_metadata`, `auth.cimd`: no remote uses OAuth
- n/a `auth.secret_in_url`: no templated URL

### tool hygiene: 100 (weight 30)

- pass `tools.descriptions`: every tool has a description
- pass `tools.description_length`: descriptions are concise
- pass `tools.schemas`: every tool has an object input schema
- pass `tools.annotations`: 4 of 4 tools declare readOnlyHint or destructiveHint
- pass `tools.directory_hints`: every tool declares readOnlyHint, destructiveHint, idempotentHint and openWorldHint
- pass `tools.token_cost`: about 984 tokens to load every tool
- pass `tools.api_dump`: tools are not a one-to-one API dump

### stability: 100 (weight 15)

- pass `stability.changes`: no tool changes in 30 days
- pass `stability.rug_pull`: no tool changed its meaning under the same name

### dependencies: n/a (weight 15)

- n/a `deps.known_vulns`, `deps.mcp_sdk_version`, `deps.resolvable`: no npm or PyPI package

- tools: 4, about 984 tokens to load them all
- tool set hash: 715141180d3c235a6a85ffe31dbb281b
- badge: [![protogrid quality](https://protogrid.dev/badge/io.github.socraticstatic/chart-color-system.svg)](https://protogrid.dev/servers/io.github.socraticstatic/chart-color-system)
- Checks run on what our credential-free, read-only probes observe; tools are never called and no code audit is performed.

### Tool changes

_No tool definition changes recorded._

## Remotes

- https://chart-color-mcp.vercel.app/mcp (streamable-http, auth none, reachable true, uptime30d 1)

## Packages

_none_

## Tools (4)

- `audit_palette`: 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.
- `build_ramp`: 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).
- `simulate_palette`: 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.
- `solve_palette`: 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.