This sample color theme extension contains two TextMate themes.
Text Mate themes describe the theming rules used for syntax highlighting. Each rule consists of one or more scope selectors and a set of styles. To learn more about scopes and how they're used, check out the color theme documentation.
You can directly use .tmTheme files in your extensions or import/convert them with VS Code's extension generator yo code.
Press F5 to open a new window with your extension loaded.
Open File > Preferences > Color Themes (or Code > Preferences > Color Theme on macOS), and pick Sample Light or Sample Dark.
Open a file that has a language associated. The languages' configured grammar will tokenize the text and assign 'scopes' to the tokens. To examine these scopes, invoke the Inspect TM Scopes command from the Command Palette (Ctrl+Shift+P or Cmd+Shift+P on Mac) .
You can relaunch the extension from the debug toolbar after making changes to the files listed above.
You can also reload (Ctrl+R or Cmd+R on Mac) the VS Code window with your extension to load your changes.