This add-on was previously Automatic Theme Switcher for Windows Dark Mode, which automatically switched between dark/light themes to match Windows Dark Mode (which required Windows 10 October 2018 Update or later), and used the settings autoDarkMode.darkTheme and autoDarkMode.lightTheme. The extension was partly inspired by a version for macOS Mojave: auto-dark-mode.
However, since VS Code V1.42 (January 2020), a standard setting has been available: window.autoDetectColorScheme. This performs the same action in a cross-platform way and should be used instead. If this setting is not enabled during start-up, the extension will prompt to change the setting, but the original behaviour will continue.