Lexicon

A Semantic Syntax Theme System — A color vocabulary for code.

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Overview

Lexicon is a semantic syntax theme system for C# in Visual Studio using Codist (GitHub · Marketplace). Every color carries meaning—once you learn the vocabulary, any C# codebase becomes easier to read.

You already know the difference between a class and a struct. Between an if statement and a method call. Between a constant and a variable. Lexicon makes your editor know it too.

Key Features

• 🎨 11 semantic categories: types, data, control flow, exceptions, literals, and more
• 🌈 10 coordinated dark themes sharing the same semantic vocabulary
• 🔍 Designed for: code review, debugging, and onboarding to unfamiliar codebases

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The Semantic Map

Category	Semantic Role	Color
Reference Types	Heap-allocated, polymorphic types	🟣 Purple
Value Types	Stack-allocated, copy-semantic types	🔵 Blue
Interfaces	Behavioral contracts	🩵 Cyan + Italic
Callables	Methods, constructors	🟡 Yellow
Data	Fields, properties, parameters	💠 Light Blue
Control Flow	if, for, while, switch	🟠 Orange + Bold
Exceptions	try, catch, throw	🔴 Coral
String Literals	"text", $"interpolated"	🟢 Green
Literal Values	42, true, null, enum members	🟤 Amber
Namespaces	Organizational scope	🩶 Teal
Keywords	class, public, async	💜 Soft Purple

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Theme Collection

Theme	Palette	Vibe
Twilight ⭐		Evening sky, "magic hour" coding
Glacier		Arctic calm, reduced visual intensity
Ember		Late-night warmth and creative energy
Canopy		Forest canopy, organic feel
Neon		Electric city, high-energy sessions
Solstice		Solarized-inspired, calibrated precision
Whisper		Soft, library-quiet coding
Nocturne		Jewel tones on deep night
Patina		Aged copper, archival feel
Beacon		Accessibility-first, maximum contrast

Recommended starting point: Lexicon Twilight, with Beacon available as a high-contrast option.

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Installation

1. Import the Syntax Styles

1. Open Visual Studio
2. Go to Tools → Options → Codist → Syntax Highlight
3. Click Load and select the .styles file from your chosen theme folder (e.g., themes/twilight/Lexicon-Twilight.styles)

2. Register Custom Classification Types

The custom classification types (Lexicon: Exception Keyword and Lexicon: Captured Variable) must be registered in your global Codist configuration folder.

Location of the global Codist config folder:

%APPDATA%\Codist

Or typically:

C:\Users\<YourUsername>\AppData\Roaming\Codist

Steps:

1. Navigate to your Codist config folder (create it if it doesn't exist)
2. Copy ClassificationTypes.json from your theme folder to this location
   • If the file already exists, merge the items array contents
3. Restart Visual Studio for the changes to take effect

Example merge: If you already have classification types defined, add the Lexicon items to the existing array:

{
  "items": [
    // ... your existing items ...
    {
      "name": "Lexicon: Exception Keyword",
      "foreground": "#f7768e",
      "bold": true
    },
    {
      "name": "Lexicon: Captured Variable",
      "background": "#30ffa657"
    }
  ]
}

3. Install Custom Classification Rules

Copy Codist.ct.yaml from your theme folder to %APPDATA%\Codist\Codist.ct.yaml

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License

See LICENSE for details.