VSCode Theme Generator

Generate custom VSCode color themes from scratch, package them, and install them directly to VSCode.

Prerequisites

The following tools are required:

• @vscode/vsce (VSCode Extension Manager)
• code command (VSCode CLI)

Check if tools are installed:

which vsce || echo "vsce is not installed"
which code || echo "code command is not installed"

Install if missing:

# vsce
npm install -g @vscode/vsce

# code command: In VSCode, press Cmd+Shift+P → "Shell Command: Install 'code' command in PATH"

Theme Builder

This skill includes a theme builder script that enables efficient theme creation by editing individual part files.

Directory Structure

<theme-id>/
├── .vscodeignore          # Excludes parts/ from .vsix
├── package.json           # Extension manifest
├── parts/                 # Edit these files to customize
│   ├── base.json          # name, type, semanticHighlighting
│   ├── colors-editor.json # Editor colors
│   ├── colors-ui.json     # UI colors (sidebar, tabs, etc.)
│   ├── colors-terminal.json # Terminal colors
│   ├── tokens.json        # Syntax highlighting
│   └── semantic.json      # Semantic token colors
└── themes/
    └── <theme-id>-color-theme.json  # Generated by merge

Builder Commands

# Initialize a new theme from template
node <skill-path>/theme-builder.js init <theme-id> "<theme-name>" [--type dark|light]

# Merge parts into final theme file
node <skill-path>/theme-builder.js merge <theme-id>

# Package as .vsix
node <skill-path>/theme-builder.js package <theme-id>

# Bump version
node <skill-path>/theme-builder.js bump <theme-id> [patch|minor|major]

Instructions

Step 1: Gather theme requirements

Ask the user for:

• Theme name (e.g., "Ocean Blue")
• Theme type: dark or light
• Color preferences (base colors, accent colors)
• Any specific style inspiration

Step 2: Initialize theme

node <skill-path>/theme-builder.js init <theme-id> "<Theme Name>" --type dark

Replace:

• <skill-path>: Path to this skill directory
• <theme-id>: lowercase with hyphens (e.g., ocean-blue)
• <Theme Name>: display name (e.g., Ocean Blue)

Step 3: Edit part files

Edit the files in <theme-id>/parts/ to customize the theme.

parts/base.json

{
  "name": "Theme Name",
  "type": "dark",
  "semanticHighlighting": true
}

parts/colors-editor.json

Editor-related colors:

Property	Description
editor.background	Main editor background
editor.foreground	Default text color
editorLineNumber.foreground	Line number color
editorCursor.foreground	Cursor color
editor.selectionBackground	Selection highlight
editorBracketMatch.*	Matching bracket highlight
editorError.foreground	Error underline
editorWarning.foreground	Warning underline

parts/colors-ui.json

UI element colors:

Property	Description
activityBar.background	Left sidebar icon bar
sideBar.background	File explorer background
statusBar.background	Bottom status bar
titleBar.activeBackground	Window title bar
tab.activeBackground	Active tab
tab.inactiveBackground	Inactive tabs
list.activeSelectionBackground	Selected item in lists
input.background	Input field background
button.background	Button background

parts/colors-terminal.json

Terminal colors including ANSI colors:

Property	Description
terminal.background	Terminal background
terminal.foreground	Terminal text
terminal.ansiBlack - terminal.ansiWhite	ANSI colors
terminal.ansiBrightBlack - terminal.ansiBrightWhite	Bright ANSI colors

parts/tokens.json

Syntax highlighting (array of token rules):

Scope	Applies to
comment	Comments
string	String literals
keyword	if, for, const, etc.
storage.type	Type keywords
entity.name.function	Function names
entity.name.type	Type/class names
variable	Variables
constant.numeric	Numbers
entity.name.tag	HTML/XML tags
entity.other.attribute-name	Attributes

Example token rule:

{
  "scope": ["comment", "punctuation.definition.comment"],
  "settings": { "foreground": "#6A9955", "fontStyle": "italic" }
}

parts/semantic.json

Semantic token colors (optional, object format):

{
  "function": "#DCDCAA",
  "variable.readonly": "#4FC1FF"
}

Step 4: Merge and package

# Merge parts into theme file
node <skill-path>/theme-builder.js merge <theme-id>

# Package as .vsix
node <skill-path>/theme-builder.js package <theme-id>

# Install to VSCode
code --install-extension <theme-id>/<theme-id>-0.0.1.vsix

Step 5: Notify user

After installation:

Theme installed successfully! Press Cmd+K Cmd+T (Mac) or Ctrl+K Ctrl+T (Windows/Linux) to select your new theme.

Updating an Existing Theme

When updating a theme, bump the version before packaging:

# Bump version (default: patch)
node <skill-path>/theme-builder.js bump <theme-id>

# Merge and package
node <skill-path>/theme-builder.js merge <theme-id>
node <skill-path>/theme-builder.js package <theme-id>

# Install updated theme
code --install-extension <theme-id>/<theme-id>-<new-version>.vsix

Color Design Tips

Dark themes

• Background: #1a1a2e to #2d2d44
• Foreground: #d4d4d4 to #eaeaea
• Limit accent colors to 1-2

Light themes

• Background: #ffffff to #f5f5f5
• Foreground: #1a1a1a to #333333
• Use muted accent colors

Transparency

Use alpha channel for subtle effects: #ffffff40 (last two digits = opacity 00-ff)

Accessibility

Aim for reasonable contrast between text and background for readability.

Troubleshooting

Theme not appearing

Run Developer: Reload Window from command palette.