Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add mgifford/accessibility-skills --skill color-contrastgit clone --depth 1 https://github.com/mgifford/accessibility-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/mgifford/accessibility-skills/color-contrast)<a href="https://agentmods.dev/skills/mgifford/accessibility-skills/color-contrast"><img src="https://agentmods.dev/badge/skills/mgifford/accessibility-skills/color-contrast/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/mgifford/accessibility-skills/color-contrast"><img src="https://agentmods.dev/badge/skills/mgifford/accessibility-skills/color-contrast.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00100 | $0.04399 |
| Opus 5 | $0.00050 | $0.02200 |
| Sonnet 5 | $0.00020 | $0.00880 |
| Haiku 4.5 | $0.00010 | $0.00440 |
Grade A, and why
color-contrast scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 11d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
The source is not reproduced here
Licensed AGPL-3.0
The repository is licensed AGPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 11d ago First seen · 450 lines · 100 tokens per session scan A a4f4eec91187
color-contrast is a skill published in the GitHub repository mgifford/accessibility-skills (44 stars, last pushed 2d ago), licensed AGPL-3.0. It adds 100 tokens to every session and 4,399 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
ui-ux-laws
Priority-ordered rulebook of core UX/UI laws, cognitive-psychology principles, Nielsen's usability heuristics, and accessibility requirements that Claude must actively apply (not just cite) whenever it designs, builds, redesigns, reviews, or critiques any user interface — websites, web/mobile apps, dashboards, forms…
wes-bos-sick-picks
Research-first workflow for building frontend UI components (any framework), in the spirit of Wes Bos. Use when designing or implementing a UI component, layout, interaction, or CSS/HTML feature and you want a modern, accessible, best-practice solution rather than a first guess. Researches pitfalls and platform…
design-board
Full UX/UI design review panel — 6 opinionated design leaders (Jony Ive, Amir Salihefendic, Jesse Patel, Joe Gebbia, Katie Dill, Notion Designer) critique your design with brutal honesty, deliberate together, score on 5 principles, and implement fixes. Works with .pen files, HTML/CSS/JS projects, and Figma.
amir-salihefendic
Amir Salihefendic (Todoist/Doist) design critique — calm technology, daily-use sustainability, anti-bloat. Brutally honest UX/UI feedback focused on productivity and the day-500 experience. Scores on 5 principles and implements fixes.
jesse-patel
Jesse Patel (WorkFlowy) design critique — radical simplicity, one interaction pattern, keyboard-first. Brutally honest UX/UI feedback focused on reducing concept count and interaction complexity. Scores on 5 principles and implements fixes.
joe-gebbia
Joe Gebbia (Airbnb) design critique — trust through design, emotional arcs, belonging. Brutally honest UX/UI feedback focused on how the user FEELS at every step. Scores on 5 principles and implements fixes.