ux-theming

ux-theming is a skill for Claude Code, Codex from microsoft/vscode. It costs 44 tokens per session (1,742 once invoked), scanned A, original, MIT.

VS Code guidance for connecting widget colours and styles to light, dark, and high-contrast themes.

In plain words
What is it for?
Use it when registering colour tokens, styling widgets, choosing existing theme colours, and adding focus or contrast indicators.
Why use it?
It helps UI components remain readable and visibly focused across different themes, including high-contrast mode.

Skill for Claude CodeCodex

About the project

Visual Studio Code is a code editor that supports editing, navigating, understanding, debugging, and extending software projects. Developers use it for the edit-build-debug cycle, and the catalogue add-ons provide skills, instructions, and agents for working within the editor.

microsoft/vscode · 190,863 stars · on GitHub

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.

agentmods
npx agentmods add skills/microsoft/vscode/ux-theming
Any agent
npx skills add microsoft/vscode --skill ux-theming
Clone the repo
git clone --depth 1 https://github.com/microsoft/vscode

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 ux-theming

README.md
[![agentmods](https://agentmods.dev/badge/skills/microsoft/vscode/ux-theming.svg)](https://agentmods.dev/skills/microsoft/vscode/ux-theming)
Your own site
<a href="https://agentmods.dev/skills/microsoft/vscode/ux-theming"><img src="https://agentmods.dev/badge/skills/microsoft/vscode/ux-theming.svg" alt="Measured on agentmods" height="20"></a>
Per session 44 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,742 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00044 $0.01742
Opus 5 $0.00022 $0.00871
Sonnet 5 $0.00009 $0.00348
Haiku 4.5 $0.00004 $0.00174

Measured yesterday against content hash 2579f2ee488e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

ux-theming 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 yesterday.

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.

.github/skills/ux-theming/SKILL.md · 163 lines

How it starts

The opening of the file, as written. The whole thing — 163 lines — stays where its author put it; the contents beside it link to each section on GitHub.

This skill covers color registration, CSS variable usage, widget style patterns, focus indicators, and high-contrast theme requirements.


1. Registering Colors

File: src/vs/platform/theme/common/colorUtils.ts

export const myWidgetBackground = registerColor('myWidget.background',
    { light: '#ffffff', dark: '#252526', hcDark: Color.black, hcLight: Color.white },
    nls.localize('myWidgetBackground', "Background color of My Widget."));

Rules:

  • Provide defaults for all four theme types: light, dark, hcDark, hcLight.
  • HC themes must use solid colors (avoid transparency) and set explicit borders via contrastBorder.
  • Use color transforms for derived colors: transparent(), darken(), lighten(), oneOf().
  • Reference existing colors when possible instead of hardcoding hex values.

2. Color Categories

File Colors
src/vs/platform/theme/common/colors/baseColors.ts foreground, focusBorder, contrastBorder, text links
src/vs/platform/theme/common/colors/editorColors.ts Editor widgets, find match, errors/warnings
src/vs/platform/theme/common/colors/inputColors.ts Input, toggle, validation
src/vs/platform/theme/common/colors/listColors.ts List/tree selection, focus, hover, drop
src/vs/platform/theme/common/colors/miscColors.ts Badge, scrollbar, progress bar, sash
src/vs/workbench/common/theme.ts Tabs, sidebar, status bar, panels, editor groups, banner

3. Using Colors in CSS

Colors are injected as CSS custom properties on .monaco-workbench:

Color ID: editor.background
CSS variable: --vscode-editor-background
Usage: var(--vscode-editor-background)

Conversion functions in colorUtils.ts:

  • asCssVariable(colorId)'var(--vscode-editor-background)'
  • asCssVariableName(colorId)'--vscode-editor-background'

In CSS files, reference directly:

.my-widget {
    background-color: var(--vscode-editor-background);
    color: var(--vscode-foreground);
    border: 1px solid var(--vscode-contrastBorder);
}

Read the full file on GitHub · 163 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. yesterday First seen · 163 lines · 44 tokens per session scan A 2579f2ee488e

Subscribe to this mod's changes

ux-theming is a skill published in the GitHub repository microsoft/vscode (190,863 stars, last pushed today), licensed MIT. It adds 44 tokens to every session and 1,742 once invoked, about $0.0002 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 2026-09-03.

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