# Zovo Palette Lab (remote · contrast-checker.zovo.one)

WCAG contrast & palettes

- Trust score: 74/100 (medium)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-10-23

## Components

- remote · `contrast-checker.zovo.one`: 74/100 (this document), [markdown](https://verifymcp.io/servers/theluckystrike-contrast-checker/contrast-checker.md), [page](https://verifymcp.io/servers/theluckystrike-contrast-checker/contrast-checker)

## Channel facts

- Endpoint: `https://contrast-checker.zovo.one/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `1.0.0`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-10-23.

- **Endpoint Security**: 80/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one.
  - HTTPS is enforced; there's no plaintext access path.
  - The HSTS (Strict-Transport-Security) header is present.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 74/100
  - 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).
  - AI-judged instruction clarity (good).
  - Context-footprint check failed: tool/resource definitions use about 1102 tokens (~275/item across 4 items; 3 tools + 1 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 3/100
  - Stability observed for 1 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
  - Structured output schemas are declared (100% of tools); any adoption earns full credit.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 3 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 5 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.
  - Supports UI / widget rendering.

## Install

### How do I install the Zovo Palette Lab MCP server?

Zovo Palette Lab is a hosted endpoint at https://contrast-checker.zovo.one/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add --transport http theluckystrike-contrast-checker 'https://contrast-checker.zovo.one/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "theluckystrike-contrast-checker": {
      "url": "https://contrast-checker.zovo.one/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "theluckystrike-contrast-checker": {
      "type": "http",
      "url": "https://contrast-checker.zovo.one/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.theluckystrike-contrast-checker]
url = "https://contrast-checker.zovo.one/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "theluckystrike-contrast-checker": {
      "type": "remote",
      "url": "https://contrast-checker.zovo.one/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add theluckystrike-contrast-checker --url 'https://contrast-checker.zovo.one/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  theluckystrike-contrast-checker:
    url: "https://contrast-checker.zovo.one/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "theluckystrike-contrast-checker": {
      "Transport": "http",
      "Url": "https://contrast-checker.zovo.one/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add theluckystrike-contrast-checker -t streamable-http -u 'https://contrast-checker.zovo.one/mcp'
```

### Other

```json
{
  "mcpServers": {
    "theluckystrike-contrast-checker": {
      "type": "http",
      "url": "https://contrast-checker.zovo.one/mcp"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-10-23 (score 74, +1)

- [functional improvement] Stability: unverified → 0.03

### 2026-10-22 (score 73)

First indexed and scored.

## MCP tools (3)

### `check_color_contrast` (~492 tokens)

Check color contrast

Use this when the user wants to know whether a text, icon or border colour has enough contrast against a background: a WCAG contrast checker for one colour pair (e.g. "does white text on #F59E0B pass WCAG AA", "contrast ratio of #767676 on white", "what text color for this background"). Returns the computed WCAG 2.x ratio (truncated to 2 decimals, rounded down), AA/AAA results for normal text, large text and UI components, a verdict for a given font size, APCA Lc as draft information, and the nearest passing colours for AA and AAA (darker and lighter, same OKLCH hue and chroma). Accepts hex, 8-digit hex with alpha, rgb(), hsl(), hwb(), lab(), lch(), oklab(), oklch(), color(display-p3 ...) and CSS colour names; wide-gamut colours are clipped to sRGB with a note. Does not read colours from images or web pages, resolve CSS variables or currentColor, or check gradients as a whole (check each stop). For 3 or more colours use check_palette_contrast.

Input parameters:

- `adjust` (string): Which colour the suggested fixes change, e.g. foreground. auto (default) changes the more colourful of the two, so brand colours keep their hue.
- `background` (string, required): Background colour behind it, e.g. #FFFFFF, white or #1E293B. A translucent background is composited over white.
- `bold` (boolean): Optional: true when that text is bold (font-weight 700+), e.g. true. Bold text from 18.66px counts as large text.
- `font_size_px` (number): Optional text size in CSS pixels for a single verdict on that text, e.g. 16. 18pt = 24px; 14pt = about 18.66px.
- `foreground` (string, required): Text, icon or border colour, e.g. #767676, #1E6FD980 (8-digit hex with alpha), rgb(118, 118, 118), hsl(214 76% 48%), oklch(55% 0.18 255) or a CSS colour name such as navy. Translucent colours are com…

Output parameters:

- `apca` (object)
- `background` (object)
- `fixes` (object)
- `foreground` (object)
- `kind` (string)
- `ratio` (number)
- `ratio_4dp` (number)
- `request` (object)
- `warnings` (array)
- `wcag` (object)
- `your_text`

### `check_palette_contrast` (~260 tokens)

Check palette contrast

Use this when the user has a colour palette (2 to 12 colours) and wants to know which combinations are accessible: "check contrast of my color palette", "which of these colors can I use for text", "accessible color palette checker". Returns the full pairwise WCAG 2.x contrast matrix (ratios truncated, rounded down), which pairs pass AA/AAA for text or 3:1 for large text and UI, and a recommended text colour for each background (a palette colour that passes AA, otherwise black or white). Does not generate new colours; use generate_accessible_palette for a tonal scale and check_color_contrast for fixes to one pair.

Input parameters:

- `colors` (array, required): 2 to 12 colours to test against each other, e.g. ["#1E6FD9", "#F59E0B", "#FFFFFF", "#111827"]. Hex, rgb(), hsl(), hwb(), lab(), lch(), oklab(), oklch(), color(display-p3 ...) or CSS names; translucen…
- `names` (array): Optional labels in the same order as colors, e.g. ["Primary", "Accent", "Surface", "Ink"].

Output parameters:

- `best_text` (array)
- `colors` (array)
- `kind` (string)
- `matrix` (array)
- `request` (object)
- `summary` (object)
- `text_pairs` (array)
- `warnings` (array)

### `generate_accessible_palette` (~250 tokens)

Generate accessible palette

Use this when the user wants an accessible colour scale or palette built from one colour: "color palette generator from hex", "generate a 50-950 scale from #1E6FD9", "tailwind color palette generator", "accessible color palette for my website". Builds an 11-step 50-950 tonal scale in OKLCH with the base hue, where 50-400 pass AA with black text, 500 passes AA with both white and black text, 600 passes AA with white text and 700-950 pass AAA with white text, and each ratio is reported. Returns CSS custom properties and a Tailwind config as downloads. Does not pick colours by mood or brand meaning and does not extract palettes from images.

Input parameters:

- `base_color` (string, required): Brand or base colour to build the 50-950 scale from, e.g. #1E6FD9, rgb(30, 111, 217), oklch(55% 0.18 255) or teal.
- `name` (string): Token name for CSS variables and the Tailwind colour key, e.g. brand (gives --brand-500). Default brand.

Output parameters:

- `base` (object)
- `css` (string)
- `downloads` (object)
- `kind` (string)
- `name` (string)
- `pairs` (array)
- `request` (object)
- `rules` (array)
- `steps` (array)
- `tailwind` (string)
- `warnings` (array)

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/theluckystrike-contrast-checker/contrast-checker#diagnostics

## Score history

- 2026-10-23: 74
- 2026-10-22: 73

## Common questions

### What is the Zovo Palette Lab MCP server?

Zovo Palette Lab is an MCP server listed in the public MCP registry as io.github.theluckystrike/contrast-checker. WCAG contrast & palettes. This page covers its hosted endpoint (https://contrast-checker.zovo.one/mcp).

### Is the Zovo Palette Lab MCP server safe to use?

Zovo Palette Lab scores 74 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the Zovo Palette Lab MCP server expose?

Zovo Palette Lab exposes 3 tools: check_color_contrast, check_palette_contrast, generate_accessible_palette. Their descriptions and schemas cost roughly 1,002 tokens of context every time the server is loaded.

### Does the Zovo Palette Lab MCP server require authentication?

No. We connected to Zovo Palette Lab without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

### Is the Zovo Palette Lab MCP server still maintained?

Zovo Palette Lab is still listed as active in the MCP registry. We last reached this channel on 23 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

## Links

- Remote endpoint: https://contrast-checker.zovo.one/mcp
- Website: https://contrast-checker.zovo.one/
- Changelog RSS feed: https://verifymcp.io/servers/theluckystrike-contrast-checker/contrast-checker.xml
- Changelog JSON feed: https://verifymcp.io/servers/theluckystrike-contrast-checker/contrast-checker.json
- HTML version of this page: https://verifymcp.io/servers/theluckystrike-contrast-checker/contrast-checker