color_contrast
shallowtools.clean/mcp · Verify this server
Use this when checking whether a text/background color pair meets WCAG 2.x accessibility contrast. Computes the relative-luminance contrast ratio (1-21, rounded to 2 decimals) and returns pass/fail booleans for normal and large text at AA and AAA levels (thresholds 4.5 / 7 / 3 / 4.5), plus a suggested passing foreground hex when normal-text AA fails (null when it already passes or none is found). Accepts 3- or 6-digit hex, with or without a leading '#'; echoed colors are normalized to 6-digit hex. Deterministic: same input, same output. Example: {foreground:'777', background:'fff'} -> ratio 4.48, normalAA false, largeAA true, suggestedForeground '#767676'.
1 trials · measured 55 days ago
color_contrast scores 100.0/100 on Vouch's measured behaviour index, from 1 real invocation trials against tools.clean/mcp, measured 25 Aug 2026 under methodology v0.2.0. Every measured component scored 100.
Component breakdown
| Component | Weight | Value |
|---|---|---|
| Reliability | 35% | not applicable |
| Schema integrity | 25% | 100.0 |
| Failure behaviour | 15% | not applicable |
| Latency | 15% | not applicable |
| Concurrency | 10% | not applicable |
Tool details
- Transport
- remote + stdio
- Credential class
- self-provisionable
- Category
- Developer infrastructure
- Input schema
- not declared
- Output schema
- not declared
- Side-effect classification
- unclassified
Score history
| Day | Score | Tier | Methodology |
|---|---|---|---|
| 2026-08-25 | 100.0 | shallow | v0.2.0 |
Probe evidence
| Probe | Outcomes |
|---|---|
| schema_integrity | pass: 1 |
Raw request/response logs are not archived yet — the outcome counts above are drawn directly from every recorded trial.
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[](https://vouch.tools/tools/f66823fc-eafc-48cf-aa2c-aff446f1ded9)