VS Theme (.vstheme)

Visual Studio styling based on .vstheme files. Includes built-in VS2015 and VS2022 variants and supports loading custom .vstheme or .vstheme.gz (gzip-compressed) files.

Installation

dotnet add package Dirkster.AvalonDock.Themes.VS

Built-in Variants

VS2026

Visual Studio 2026 replaced the XML .vstheme format with a JSON-based override format (see Make Visual Studio look the way you want). The built-in VS2026 variants apply the Fluent accent and the new tokens that color the window/tool headers and tab strips independently from the rest of the shell:

dockManager.Theme = new VS2026DarkTheme();
dockManager.Theme = new VS2026LightTheme();
dockManager.Theme = new VS2026BlueTheme();

VS2022

dockManager.Theme = new VS2022DarkTheme();
dockManager.Theme = new VS2022LightTheme();
dockManager.Theme = new VS2022BlueTheme();

VS2015

dockManager.Theme = new VS2015DarkTheme();
dockManager.Theme = new VS2015LightTheme();
dockManager.Theme = new VS2015BlueTheme();

Loading Custom .vstheme Files

From a File Path

dockManager.Theme = new VsTheme("path/to/custom.vstheme");

From a Stream

using var stream = File.OpenRead("custom.vstheme");
dockManager.Theme = new VsTheme(stream);

The VsTheme constructor auto-detects gzip compression (via magic bytes 0x1F 0x8B), so both plain .vstheme and .vstheme.gz files work with the stream constructor.

From Gzip-Compressed Bytes

For embedded resources stored as .vstheme.gz, load the raw bytes directly:

byte[] gzipBytes = VsThemeResourceLoader.Load(
    Assembly.GetExecutingAssembly(),
    "MyApp.Resources.mytheme.vstheme.gz");

dockManager.Theme = new VsTheme(gzipBytes);

From a Pre-Parsed Palette

var palette = VsThemeParser.ParseFile("custom.vstheme");
dockManager.Theme = new VsTheme(palette);

Loading Custom VS2026 JSON Files

VS2026 stores theme customizations as JSON. The files are override only — they list only the color tokens that were changed — and are shared by dropping them into %LOCALAPPDATA%\Microsoft\VisualStudio\18.0_xxxxxxxx\ColorThemes, where the file name matches the theme being overridden (e.g. dark.json overrides Dark).

A VS2026 JSON file is a flat array of { "Name", "Category", "Background" } entries with 8-digit AARRGGBB color values:

[
  { "Name": "EnvironmentHeader", "Category": "5af241b7-...", "Background": "FFF5CC84" },
  { "Name": "EnvironmentTab",    "Category": "5af241b7-...", "Background": "FFF5CC84" },
  { "Name": "EnvironmentBackground", "Category": "5af241b7-...", "Background": "FFCCD5F0" }
]

Use VsTheme.FromJson to load one. Because the file is override-only, pass a base palette to layer the overrides on top of a full theme:

// Use a built-in VS theme palette as the base, then apply the JSON overrides.
using var baseStream = File.OpenRead("vs2022dark.vstheme");
var basePalette = VsThemeParser.Parse(baseStream);

dockManager.Theme = VsTheme.FromJson("cool-breeze.json", basePalette);

If no base palette is supplied, only the tokens present in the JSON are used and all other colors fall back to the resource builder’s defaults. The JSON can also be loaded from a stream via VsTheme.FromJson(Stream, ...).

XAML Markup Extension

<DockingManager Theme="{vs:VsTheme Path=vs2015blue.vstheme}" />

The Path can be absolute or relative to the application directory.

Parsing API

VsThemeParser extracts a VsThemeColorPalette from .vstheme files (the Environment category):

Method	Description
`VsThemeParser.Parse(Stream)`	Parse from a stream (auto-detects gzip)
`VsThemeParser.ParseFile(string)`	Parse from a file path
`VsThemeParser.ParseGZip(byte[])`	Parse from gzip-compressed bytes

VsJsonThemeParser extracts the same VsThemeColorPalette from VS2026 JSON files:

Method	Description
`VsJsonThemeParser.Parse(string)`	Parse from a JSON string
`VsJsonThemeParser.Parse(Stream)`	Parse from a stream
`VsJsonThemeParser.ParseFile(string)`	Parse from a file path

Because VS2026 JSON files are override-only, combine them with a base palette using basePalette.Merge(overridePalette) before building a theme.

The returned VsThemeColorPalette provides lookup methods:

var palette = VsThemeParser.ParseFile("mytheme.vstheme");

Color? bg = palette.GetBackground("ToolWindowBackground");
Color fg = palette.GetForegroundOrDefault("ToolWindowText", Colors.White);
bool has = palette.Contains("AccentMedium");