color_contrast
WCAG Color Contrast Checker — Contrast ratio between two hex colors plus WCAG 2.x AA/AAA pass/fail for normal and large text.
This record as markdown: /tools/com-wingmanprotocol-agent-gateway/color-contrast.md
What color_contrast does on Gateway
AI agents call color_contrast to retrieve information from Gateway without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
background | string | Yes | Background hex color, e.g. '#FFFFFF' or 'fff' |
foreground | string | Yes | Foreground hex color, e.g. '#111111' or '111' |
Parameters from the server's own tool schema.
Why color_contrast is rated Low
This is a straightforward read-only utility that analyzes accessibility compliance. It retrieves/computes contrast information from two color inputs and returns conformance results. No state changes, no data writes, no destructive operations, no code execution, no financial impact. Clear fit for Read category with minimal risk.
From the tool's definition Tool performs analysis and checking of color contrast ratios against WCAG standards. Returns pass/fail results and contrast measurements with no data modification, deletion, or external side effects. Purely informational output based on input hex color values.
Attacks that exploit this kind of access
The rule that runs color_contrast safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Gateway, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For color_contrast, this is the rule to start with:
color_contrast is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Gateway, apply this rule, and every color_contrast call is checked against it from then on.
Questions about color_contrast
WCAG Color Contrast Checker — Contrast ratio between two hex colors plus WCAG 2.x AA/AAA pass/fail for normal and large text. It is categorised as a Read tool in the Gateway MCP Server, which means it retrieves data without modifying state.
color_contrast accepts 2 parameters: background, foreground. Required: background, foreground. The full parameter table on this page comes from the server's own tool schema.
Register the Gateway MCP server in PolicyLayer and add a rule for color_contrast: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Gateway. Nothing to install.
color_contrast is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the color_contrast rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for color_contrast. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
color_contrast is provided by the Gateway MCP server (https://wingmanprotocol.com/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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