canon-color-blindness

canon-color-blindness is a skill for Claude Code, Codex from Dragoon0x/canon. It costs 87 tokens per session (928 once invoked), scanned A, original, MIT.

A set of guidelines for making interfaces understandable to people whose eyes distinguish some colours differently, known as colour vision deficiency or colour blindness.

In plain words
What is it for?
Use it when checking status indicators, forms, charts, and colour palettes for red-green, blue-yellow, or limited colour perception.
Why use it?
It prevents colour from being the only way users can tell states apart, such as errors, online status, or chart lines.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it when checking status indicators, forms, charts, and colour palettes for red-green, blue-yellow, or limited colour perception.

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Install with agentmods
npx agentmods add skills/dragoon0x/canon/canon-color-blindness
Install

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.

Any agent
npx skills add Dragoon0x/canon --skill canon-color-blindness
Clone the repo
git clone --depth 1 https://github.com/Dragoon0x/canon

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for canon-color-blindness

README.md
[![agentmods](https://agentmods.dev/badge/skills/dragoon0x/canon/canon-color-blindness/github.svg)](https://agentmods.dev/skills/dragoon0x/canon/canon-color-blindness)
Your own site
<a href="https://agentmods.dev/skills/dragoon0x/canon/canon-color-blindness"><img src="https://agentmods.dev/badge/skills/dragoon0x/canon/canon-color-blindness/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.

agentmods 80×15 button for canon-color-blindness

Your own site · 80×15
<a href="https://agentmods.dev/skills/dragoon0x/canon/canon-color-blindness"><img src="https://agentmods.dev/badge/skills/dragoon0x/canon/canon-color-blindness.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 87 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 928 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00087 $0.00928
Opus 5 $0.00044 $0.00464
Sonnet 5 $0.00017 $0.00186
Haiku 4.5 $0.00009 $0.00093

Measured 11d ago against content hash c356871d4371, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

canon-color-blindness 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.

source/skills/canon-color-blindness/SKILL.md · 79 lines

How it starts

The opening of the file, as written. The whole thing — 79 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CANON · Color Blindness

8% of men and 0.5% of women have some form of color vision deficiency. Designing for them isn't a special case; it's designing for 1 in 12 of your users.

The cardinal rule

Color is never the only signal. Every piece of information conveyed by color must also be conveyed by text, shape, pattern, or position. WCAG 1.4.1.

Bad (color only) Good (color + secondary signal)
Red dot = error Red dot + "Error" text label
Green line vs red line on chart Solid line vs dashed line + legend
Green = online, gray = offline Filled circle = online, empty ring = offline
Red border on invalid field Red border + error icon + error message below

Types of CVD

Type Prevalence (male) Affects
Deuteranopia (green-blind) ~5% Red-green confusion
Protanopia (red-blind) ~2.5% Red-green confusion
Tritanopia (blue-blind) ~0.01% Blue-yellow confusion
Achromatopsia (total) ~0.003% No color perception

Red-green is overwhelmingly the most common. Blue-yellow is rare. Designing for red-green covers the vast majority.

Safe palette strategies

  • Avoid relying on red vs green as opposing signals. Use red vs blue, or add icons.
  • Use lightness differences, not just hue. If two colors look the same in grayscale, they'll confuse someone with CVD.
  • Sequential palettes (light-to-dark of one hue) work well because lightness varies.
  • Categorical palettes: blue, orange, purple, brown, pink, gray — generally distinguishable across CVD types. Avoid red+green and blue+purple.

Charts specifically

  • Different line styles (solid, dashed, dotted) in addition to colors.
  • Different marker shapes (circle, square, triangle) on scatter plots.
  • Direct labels over legend when possible (avoids the color-matching task entirely).
  • Test palette in a CVD simulator (Sim Daltonism, Chrome DevTools).

Testing

  • Chrome DevTools: Rendering tab → Emulate vision deficiency → Deuteranopia / Protanopia / Tritanopia.
  • Sim Daltonism (macOS): real-time overlay.
  • Coblis (online): upload screenshot, simulate CVD.
  • Quick test: desaturate your UI to grayscale. If you can still distinguish all states, you pass.

Read the full file on GitHub · 79 lines

Changes

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.

  1. 11d ago First seen · 79 lines · 87 tokens per session scan A c356871d4371

Subscribe to this mod's changes

canon-color-blindness is a skill published in the GitHub repository Dragoon0x/canon (6 stars, last pushed 4mo ago), licensed MIT. It adds 87 tokens to every session and 928 once invoked, about $0.0004 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 2026-08-31.

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