Agent skill

Sandbox Color

by nodetool-ai in nodetool-ai/nodetool

Convert, mix, and measure colors inside a Code node or CodeAct action, with culori running in the guest

AGPL-3.0Auto-check passedDocuments & Office

Install Sandbox Color

skills CLI
$ npx skills add nodetool-ai/nodetool --skill sandbox-color -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install nodetool-ai/nodetool sandbox-color --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/nodetool-ai/nodetool.git skills-src && mkdir -p .claude/skills && cp -r skills-src/packages/sandbox-packs/sandbox-color .claude/skills/sandbox-color && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
sandbox-color
GitHub stars
560
Token cost
~236 tokens
SKILL.md length
46 words
Files
2
Skills in repo
127
Repo updated
First seen
Licence
AGPL-3.0

At a glance

Convert, mix, and measure colors inside a Code node or CodeAct action, with culori running in the guest

  • Documents & Office work in your project
  • SKILL.md covers Parse and convert, Mix and difference and Gotchas
  • Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Sandbox Color is an agent skill from nodetool-ai/nodetool. Convert, mix, and measure colors inside a Code node or CodeAct action, with culori running in the guest

Its SKILL.md is about 240 tokens, which your agent loads only when the skill is triggered. The skill folder holds 1 other file (for example `package.json`).

It sits in Documents & Office. The repository describes itself as: Agent-first Creative Workspace. The licence is AGPL-3.0.

When your agent uses it

  • Documents & Office work in your project

Example prompts

  • “/sandbox-color”

What it can do on your machine

Read from SKILL.md and the folder at commit 339f069. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    No scripts in the folder and no shell commands in SKILL.md (its code samples are javascript).

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    No URLs in SKILL.md.

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Sandbox Color loads about 236 tokens when it runs. Until then it costs about 29 tokens; SKILL.md has 46 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~29
When it runs · the whole SKILL.md, loaded when a task matches
~236

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from nodetool-ai/nodetool at commit 339f069, republished under its AGPL-3.0 licence (© nodetool-ai). 46 words, ~236 tokens.

Download SKILL.mdSave it as .claude/skills/sandbox-color/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.
name
sandbox-color
description
Convert, mix, and measure colors inside a Code node or CodeAct action, with culori running in the guest

Color in the sandbox

Specifier: @nodetool-ai/sandbox-color. One module, culori's root export. Import it at the top of the body.

Parse and convert

js
import { parse, formatHex, converter } from "@nodetool-ai/sandbox-color";

const color = parse(inputs.hex);
const rgb = converter("rgb")(color);
return { hex: formatHex(color), rgb };

Mix and difference

js
import { interpolate, formatHex, differenceCiede2000 } from "@nodetool-ai/sandbox-color";

const mix = interpolate(["#2563eb", "#f97316"]);
const mid = formatHex(mix(0.5));
const delta = differenceCiede2000()("#2563eb", "#f97316");
return { mid, delta };

Gotchas

  • Objects, not CSS strings, after parse. A parsed color is { mode, ...channels }.
  • Named imports. There is no useful default export.

© nodetool-ai, AGPL-3.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 1 other file in packages/sandbox-packs/sandbox-color of nodetool-ai/nodetool.

  • SKILL.md
  • package.json

Open the folder on GitHubat commit 339f069

Compare with similar skills

Sandbox Color next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Sandbox Color compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Sandbox Color this skillnodetool-ai/nodetool560—~236Automated safety check: PassAGPL-3.0
Markdown Article FormatterJimLiu/baoyu-skills27k6 repos~3.5kAutomated safety check: PassMIT
MarkitdownImCa0/just-laws78114 repos~3.2kAutomated safety check: NotesMIT
Obsidian MarkdownAtmosphere/atmosphere3.8k20 repos~1.3kAutomated safety check: PassApache-2.0
DOCXrvdbreemen/OTGW-firmware20733 repos~4.3kAutomated safety check: PassProprietary
Word Document Reader and WriterHKUDS/DeepTutor41k—~2.5kAutomated safety check: PassApache-2.0

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Questions about Sandbox Color

What does Sandbox Color do?

Convert, mix, and measure colors inside a Code node or CodeAct action, with culori running in the guest. Sandbox Color is an agent skill from nodetool-ai/nodetool.

When should I use Sandbox Color?

Sandbox Color fits situations like: documents & Office work in your project.

How do I install Sandbox Color in Claude Code?

Run `npx skills add nodetool-ai/nodetool --skill sandbox-color -a claude-code`. Or copy the skill folder (packages/sandbox-packs/sandbox-color in nodetool-ai/nodetool) into .claude/skills/sandbox-color in your project. Claude Code loads it when a task matches its description.

How do I install Sandbox Color in Codex?

Run `npx skills add nodetool-ai/nodetool --skill sandbox-color -a codex`. Or copy the skill folder (packages/sandbox-packs/sandbox-color in nodetool-ai/nodetool) into .agents/skills/sandbox-color in your project. Codex loads it when a task matches its description.

Can I use Sandbox Color in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add nodetool-ai/nodetool --skill sandbox-color -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/sandbox-color, .gemini/skills/sandbox-color, .github/skills/sandbox-color and .opencode/skills/sandbox-color in your project.

What does Sandbox Color need to run?

SKILL.md names no scripts, command-line tools or credentials: Sandbox Color is instructions for the agent only.

Does Sandbox Color access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Sandbox Color safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Sandbox Color use?

Sandbox Color is published under the AGPL-3.0 licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Sandbox Color use?

About 236 tokens (SKILL.md is roughly 944 characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Sandbox Color?

Skills that share tags, products or a category with Sandbox Color: Markdown Article Formatter (JimLiu/baoyu-skills, 27k stars), Markitdown (ImCa0/just-laws, 781 stars), Obsidian Markdown (Atmosphere/atmosphere, 3.8k stars) and DOCX (rvdbreemen/OTGW-firmware, 207 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Sandbox Color?

nodetool-ai (a GitHub organization) maintains it in nodetool-ai/nodetool, which has 560 GitHub stars. The repository holds 127 skills in this directory. The repository was last updated on October 10, 2026.

Source: nodetool-ai/nodetool on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.