Talebook is a self-hosted web library for managing and reading personal ebook collections built around Calibre. Individuals use it to organize, search, read, convert, download, and share books, while its catalogue skill lets coding agents manage a Talebook instance through natural-language requests.
Borrowing it
Nothing to install: this file belongs to talebook/talebook. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/talebook/talebook/master/.agents/skills/better-colors/SKILL.mdgit clone --depth 1 https://github.com/talebook/talebookWrote 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/talebook/talebook/better-colors)<a href="https://agentmods.dev/skills/talebook/talebook/better-colors"><img src="https://agentmods.dev/badge/skills/talebook/talebook/better-colors.svg" alt="Measured on agentmods" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00103 | $0.01463 |
| Opus 5 | $0.00051 | $0.00732 |
| Sonnet 5 | $0.00021 | $0.00293 |
| Haiku 4.5 | $0.00010 | $0.00146 |
Grade A, and why
better-colors 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 8d 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.
How it starts
The opening of the file, as written. The whole thing — 87 lines — stays where its author put it; the contents beside it link to each section on GitHub.
OKLCH Colors
OKLCH is a perceptually uniform color space where lightness, chroma, and hue are useful design controls. Use it when the project already uses OKLCH, when creating a new color system, or when the user asks for conversion or palette work. Otherwise preserve the project's established tokens and notation: a consistent hex or RGB token system is better than introducing a second color representation for an isolated fix. To explore interactively, visit oklch.fyi.
Quick Reference
| Category | When to use | Reference |
|---|---|---|
| Conversion | Hex/rgb/hsl to oklch | color-conversion.md |
| Palettes | Generate scales, multi-hue, dark mode | palette-generation.md |
| Contrast | APCA/WCAG checks, reporting failures, fixing on request | accessibility-contrast.md |
| Gamut & Tailwind | P3 fallbacks, @theme scales, gamut clamping |
gamut-and-tailwind.md |
| Usage | Semantic tokens, one meaning per color, primary-action emphasis, appearance variants | color-usage.md |
| Review output format | Severity scale, findings table, verification, verdict | review-output.md |
Core Principles
1. Use a Perceptual Color Space
- Respect the existing system. Do not convert notation merely because this skill was loaded. Reuse the project's semantic tokens and authoring format unless the task includes a color-system migration.
- Perceptual uniformity. Equal L steps = equal brightness.
oklch(0.5 ...)is visually mid. HSL'slightness: 50%varies wildly by hue. - Stable hue. HSL blue shifts toward purple as lightness changes. OKLCH hue stays constant across the full lightness range.
- Independent chroma. Chroma is an absolute measure of colorfulness that doesn't depend on lightness. HSL saturation does.
- Finite gamut. Not every oklch value maps to a displayable sRGB color. High-chroma values at certain hues will clip; gamut awareness is required.
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.
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.
- 8d ago First seen · 87 lines · 103 tokens per session scan A 201bf297e731
better-colors is a skill published in the GitHub repository talebook/talebook (5,744 stars, last pushed today), licensed BSD-2-Clause. It adds 103 tokens to every session and 1,463 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.
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