# Widgetbook's UI Theme

If you want to change some Widgetbook's UI colors, or want to enforce a specific theme mode, you can do so using these parameters:

| Parameter    | Description                                                                                                                     |
| ------------ | ------------------------------------------------------------------------------------------------------------------------------- |
| `lightTheme` | [`ThemeData`](https://api.flutter.dev/flutter/material/ThemeData-class.html) that is used when `themeMode` is `ThemeMode.light` |
| `darkTheme`  | [`ThemeData`](https://api.flutter.dev/flutter/material/ThemeData-class.html) that is used when `themeMode` is `ThemeMode.dark`. |
| `themeMode`  | Controls which [`ThemeMode`](https://api.flutter.dev/flutter/material/ThemeMode.html) to use. Defaults to `ThemeMode.system`.   |

```dart title=widgetbook/lib/widgetbook.config.dart
final config = Config(
  // ...
  lightTheme: ThemeData.light(), // Custom light theme
  darkTheme: ThemeData.dark(),   // Custom dark theme
  themeMode: ThemeMode.light,    // Forcing light mode
);
```