# Color-Only Signal Checker

- Human page: https://happytails.ai/en/accessibility-tools/color-only-signal-checker/
- Markdown: https://happytails.ai/en/accessibility-tools/color-only-signal-checker.md
- Structured JSON: https://happytails.ai/agents/en/accessibility-tools/color-only-signal-checker/index.json
- Visibility: public

## Tool capabilities

| Property | Value |
| --- | --- |
| Tool ID | `color-only-signal-checker` |
| Category | accessibility-tools |
| Implementation | Registered implementation. Registration alone is not a production-quality guarantee. |
| Browser execution | Use the visible action or interactive controls. |
| Browser processing | Browser; see tool notes for network behavior. |
| HTTP API | Not callable through HTTP. |
| Browser-agent interface | run_current_tool |

### Implementation notes

Flag likely color-only status signals locally; rendering and contrast still need browser review.

### Inputs and settings

Text input: Your text.

Example or placeholder shown in the interface (not a validated fixture):

```text
Type or paste your input…
```

Up to 200,000 characters. Review the settings before running.

No additional settings are declared for this tool.

### Browser-agent workflow

1. Open the human page in a browser that supports WebMCP.
2. Discover the interface exposed by that page; use its actual schema.
3. Select files on the page first when the tool requires files.
4. Call `run_current_tool` with valid input and settings.
5. Inspect the returned result or error and the displayed output. Retrieve files from the displayed download links.

Calls do not automatically copy or download results. Browser permissions still apply. Interface availability alone is not proof of successful execution.

### Planning specification

Input is limited to 200000 characters. Results are computed locally and exported as JSON.

This describes intended requirements. Use the implementation notes, interface schema and observed output to determine current support.

### Complete machine-readable capability record

```json
{
  "id": "color-only-signal-checker",
  "category": "accessibility-tools",
  "built": true,
  "requirements": "Input is limited to 200000 characters. Results are computed locally and exported as JSON.",
  "implementation": {
    "fields": [],
    "inputMaxLength": 200000,
    "inputErrorCode": "STRUCTURED_TEXT_TOO_LONG",
    "registrationFamily": "color-only-signal-checker",
    "note": "Flag likely color-only status signals locally; rendering and contrast still need browser review.",
    "experience": {
      "automatic": false,
      "single": false,
      "inputMaxLength": 200000,
      "inputMode": "text",
      "label": "Your text",
      "placeholder": "Type or paste your input…",
      "help": "Up to 200,000 characters. Review the settings before running.",
      "action": null
    },
    "mode": "explicit",
    "interactive": false
  },
  "execution": "Browser interface",
  "api": null,
  "browser_agent": {
    "supported": true,
    "name": "run_current_tool",
    "discovery": "WebMCP on the human page in a supporting browser",
    "verification": "See audit/API-AUDIT.md; availability is not verification"
  }
}
```

## Page guide

Review status designs for signals that may rely on color without text or symbols. Runs locally and returns a reviewable report.

How can we improve this tool?

Report a problem or share an idea.

Please leave out private information. Your message and the tool name go to our team via PostHog.

### How to use Color-Only Signal Checker

1. Paste the relevant HTML.
2. Run the local heuristic.
3. Review flagged status elements and download the report.

## A heuristic, not a visual audit

The checker finds likely color-only signals. Confirm contrast, focus and visual meaning in a browser.