color-ops

color-ops is a skill for Claude Code from 0xDarkMatter/claude-mods. It costs 70 tokens per session (4,187 once invoked), scanned A, original, MIT.

A practical guide to choosing and implementing colours in software interfaces. It covers colour spaces, readable contrast, palettes, CSS colour functions, design tokens, dark mode, and colour-vision differences.

In plain words
What is it for?
Use it to create palettes, check contrast, define reusable CSS colour tokens, build dark themes, and work with formats such as OKLCH and sRGB.
Why use it?
Colour values that look right can still be difficult to read, inconsistent across a design, or unsuitable for different screens and users. The guide helps developers choose colour methods and accessibility checks for each job.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: mentions subagents.

Part of the claude-mods plugin — 103 skills, 3 commands, 3 agents, 4 hooks shipped together

Good fit Use it to create palettes, check contrast, define reusable CSS colour tokens, build dark themes, and work with formats such as OKLCH and sRGB.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/0xdarkmatter/claude-mods/color-ops
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 0xDarkMatter/claude-mods --skill color-ops
Clone the repo
git clone --depth 1 https://github.com/0xDarkMatter/claude-mods

Made for: Claude Code.

Or install claude-mods, the plugin that ships this one along with the rest of its 103 skills, 3 commands, 3 agents, 4 hooks.

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 color-ops

README.md
[![agentmods](https://agentmods.dev/badge/skills/0xdarkmatter/claude-mods/color-ops/github.svg)](https://agentmods.dev/skills/0xdarkmatter/claude-mods/color-ops)
Your own site
<a href="https://agentmods.dev/skills/0xdarkmatter/claude-mods/color-ops"><img src="https://agentmods.dev/badge/skills/0xdarkmatter/claude-mods/color-ops/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 color-ops

Your own site · 80×15
<a href="https://agentmods.dev/skills/0xdarkmatter/claude-mods/color-ops"><img src="https://agentmods.dev/badge/skills/0xdarkmatter/claude-mods/color-ops.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 70 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,187 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00070 $0.04187
Opus 5 $0.00035 $0.02093
Sonnet 5 $0.00014 $0.00837
Haiku 4.5 $0.00007 $0.00419

Measured 9d ago against content hash e8196eb83f35, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

color-ops 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 9d ago.

The scan reads SKILL.md. This mod also ships 4 executable files (scripts/color-convert.js, scripts/contrast-check.js, scripts/harmony-gen.js, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

skills/color-ops/SKILL.md · 375 lines

How it starts

The opening of the file, as written. The whole thing — 375 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Color Operations

Practical color knowledge for developers and designers. Covers color spaces, accessibility, palette generation, CSS implementation, and design token architecture.

Inspired by meodai/skill.color-expert - a comprehensive 286K-word color science knowledge base with 113 reference files. This is a lightweight operational skill for everyday frontend and design work. For deep color science (spectral mixing, historical color theory, CAM16, pigment physics), install the full skill.

Color Space Decision Table

Pick the right space for the task. This is the single most impactful color decision you'll make.

Task Use Why
Perceptual color manipulation OKLCH Best uniformity for lightness, chroma, hue
CSS gradients & palettes OKLCH or color-mix(in oklab) No mid-gradient grey/brown deadzone
Gamut-aware color picking OKHSL / OKHSV Cylindrical like HSL but perceptually grounded
Normalized saturation (0-100%) HSLuv CIELUV chroma normalized per hue/lightness
Print workflows CIELAB D50 ICC standard illuminant
Screen workflows OKLAB D65 standard, perceptually uniform
Color difference (precision) CIEDE2000 Gold standard perceptual distance metric
Color difference (fast) Euclidean in OKLAB Good enough for most applications
Quick prototyping HSL Simple, fast, every tool supports it

Why HSL Falls Short

HSL is fine for quick prototyping. It fails for anything perceptual:

  • Lightness is a lie: hsl(60,100%,50%) (yellow) and hsl(240,100%,50%) (blue) have the same L=50% but vastly different perceived brightness
  • Hue is non-uniform: 20 degrees near red is a dramatic shift; 20 degrees near green is barely visible
  • Saturation doesn't correlate: S=100% dark blue still looks muted

Rule of thumb: Use HSL for throwaway work. Use OKLCH for anything that ships.

Key Distinctions

Read the full file on GitHub · 375 lines

Files

What ships with it

7 files 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.

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. 9d ago First seen · 375 lines · 70 tokens per session scan A e8196eb83f35

Subscribe to this mod's changes

color-ops is a skill published in the GitHub repository 0xDarkMatter/claude-mods (34 stars, last pushed 17d ago), licensed MIT. It adds 70 tokens to every session and 4,187 once invoked, about $0.0003 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.

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