RichTextBox for WPF incorporates several themes that allow you to customize the appearance of your grid. When you first add a C1RichTextBox control to the page, it appears similar to the following image:

This is the control's default appearance using C1SimplifiedRichTextBoxToolbar. You can change this appearance by using one of the built-in themes or by creating your own custom theme. All of the built-in themes are based on WPF Toolkit themes. The built-in themes are described and pictured below; note that in the images below, C1SimplifiedRichTextBoxToolbar has been selected to show selected styles:

Theme Name	Theme Preview
C1ThemeBureauBlack
C1ThemeExpressionDark
C1ThemeExpressionLight
C1Blue
C1ThemeOffice2007Blue
C1ThemeOffice2007Black
C1ThemeOffice2007Silver
C1ThemeOffice2010Blue
C1ThemeOffice2010Black
C1ThemeOffice2010Silver
C1ThemeShinyBlue
C1ThemeWhistlerBlue
C1ThemeOffice2013White
C1ThemeOffice2013LightGray
C1ThemeOffice2013DarkGray
C1ThemeOffice2016Black
C1ThemeOffice2016Colorful
C1ThemeOffice2016DarkGray
C1ThemeOffice2016White
C1ThemeCosmopolitanDark
C1ThemeCosmopolitan

To set an element's theme, use the ApplyTheme method. First add a reference to the theme assembly to your project, and then set the theme in code, like this:

Private Sub Window_Loaded(sender As System.Object, e As System.Windows.RoutedEventArgs) Handles MyBase.Loaded
   Dim theme As New C1ThemeExpressionDark
   ' Using ApplyTheme
   C1Theme.ApplyTheme(LayoutRoot, theme)

private void Window_Loaded(object sender, RoutedEventArgs e)
   {
      C1ThemeExpressionDark theme = new C1ThemeExpressionDark();
      //Using ApplyTheme
      C1Theme.ApplyTheme(LayoutRoot, theme);
   }

To apply a theme to the entire application, use the System.Windows.ResourceDictionary.MergedDictionaries property. First add a reference to the theme assembly to your project, and then set the theme in code, like this:

Private Sub Window_Loaded(sender As System.Object, e As System.Windows.RoutedEventArgs) Handles MyBase.Loaded
   Dim theme As New C1ThemeExpressionDark
   ' Using Merged Dictionaries
Application.Current.Resources.MergedDictionaries.Add(C1Theme.GetCurrentThemeResources(theme))
End Sub

private void Window_Loaded(object sender, RoutedEventArgs e)
   {
      C1ThemeExpressionDark theme = new C1ThemeExpressionDark();
      //Using Merged Dictionaries        Application.Current.Resources.MergedDictionaries.Add(C1Theme.GetCurrentThemeResources(theme));
   }

Note that this method works only when you apply a theme for the first time. If you want to switch to another ComponentOne theme, first remove the previous theme from Application.Current.Resources.MergedDictionaries.