WPF

<Window>
  <Grid>
    <CustomTextBox />
    <CustomTextBox />
    <Label />
    <Label />
  </Grid>
</Window>

<Window>
  <Window.Resources>
    <XmlDataProvider x:Key="configdata"/>
    <XmlDataProvider x:Key="servodata"/>
  </Window.Resources>
  <Grid>
    <TabControl>
      <TabItem>
        <Grid>
        <ScrollViewer>
          <TabControl ItemsSource="{Binding Source={StaticResource configdata}, XPath=PROGRAM/CONFIG_PAGE}">
              <TabControl.ItemTemplate>
                <DataTemplate>
                  <TextBlock Text="{Binding XPath=@page_title}"/>
                </DataTemplate>
              </TabControl.ItemTemplate>
              <TabControl.ContentTemplate>
                <DataTemplate>
                  <toolkit:DataGrid ItemsSource="{Binding XPath=DATA}">
                    <toolkit:DataGrid.Columns>
                      <toolkit:DataGridTextColumn Binding="{Binding XPath=DESCRIPTION}"/>
                      <toolkit:DataGridTextColumn Binding="{Binding XPath=VALUE}"/>
                    </toolkit:DataGrid.Columns>
                  </toolkit:DataGrid>
                </DataTemplate>
              </TabControl.ContentTemplate>
            </TabControl>
          </ScrollViewer>
        </Grid>
      </TabItem>
      <TabItem>
        <Grid>
          <TabControl>
            <TabItem>
              <Grid>
                <toolkit:DataGrid ItemsSource="{Binding Source={StaticResource configdata}, XPath=IO/Inputs/Input}">
                  <toolkit:DataGrid.Columns>
                    <toolkit:DataGridTextColumn Binding="{Binding XPath=DESCRIPTION}"/>
                    <toolkit:DataGridTextColumn Binding="{Binding XPath=VALUE}"/>
                    <toolkit:DataGridTextColumn Binding="{Binding XPath=METRIC_VALUE}"/>
                  </toolkit:DataGrid.Columns>
                </toolkit:DataGrid>
              </Grid>
            </TabItem>
            <TabItem>
              <Grid>
                <toolkit:DataGrid ItemsSource="{Binding Source={StaticResource configdata}, XPath=IO/Outputs/Output}">
                  <toolkit:DataGrid.Columns>
                    <toolkit:DataGridTextColumn Binding="{Binding XPath=DESCRIPTION}"/>
                    <toolkit:DataGridTextColumn Binding="{Binding XPath=VALUE}"/>
                    <toolkit:DataGridTextColumn Binding="{Binding XPath=METRIC_VALUE}"/>
                  </toolkit:DataGrid.Columns>
                </toolkit:DataGrid>
              </Grid>
            </TabItem>
          </TabControl>
        </Grid>
      </TabItem>
      <TabItem>
    	<Grid>
          <toolkit:DataGrid ItemsSource="{Binding Source={StaticResource servodata}, XPath=DATA}">
            <toolkit:DataGrid.Columns>
              <toolkit:DataGridTextColumn Binding="{Binding XPath=DESCRIPTION}"/>
              <toolkit:DataGridTextColumn Binding="{Binding XPath=VALUE}"/>
              <toolkit:DataGridTextColumn Binding="{Binding XPath=METRIC_VALUE}"/>
            </toolkit:DataGrid.Columns>
          </toolkit:DataGrid>
        </Grid>
      </TabItem>
    </TabControl>
    <Button/>
    <Button />
  </Grid>
</Window>

Why explicit Style defined in a theme Which had been applied for one control aren't  update when change the Theme ?.

Main.xaml: (This is a resume of main.xaml , to see full have a look the attached file)

<UserControl>
    <Grid x:Name="LayoutRoot" Background="White" >
        <!--[PROBLEM]: This Border Style doesn't refresh when the Theme changed-->
        <Border Style="{StaticResource BorderStyle2}">
            <Button Click="Change_to_Dark_Click"
                        Height="20">Select Dark Theme</Button>
        </Border>
    </Grid>
</UserControl>


Main.xaml.cs : (This is a resume of main.xaml.cs, to see full have a look the attached file)
       private void Change_to_Dark_Click(object sender, RoutedEventArgs e)
        {
            //Cleannig
            App.Current.Resources.Clear();
            App.Current.Resources.MergedDictionaries.Clear();
            Theme.SetApplicationThemeUri(App.Current, null);

            Uri themeUri = new Uri("/Controls.Dark;component/Generic.xaml", UriKind.RelativeOrAbsolute);
            Theme.SetApplicationThemeUri(Application.Current, themeUri);
        //The theme changed but the style of Border doesn't change.
    }

There is a Controls project "Controls.csproj" (to see full have a look the attached file) with:
Generic.xaml
Style.xaml
ButtonCustomized.xaml

There are 2 themes projects  created like this "Controls.Dark.csproj" (to see full have a look the attached file):
Generic.xaml
Style.xaml

Generic.xaml

<ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:controls="clr-namespace:Controls;assembly=Controls">
    <ResourceDictionary.MergedDictionaries>
        <ResourceDictionary Source="/Controls.Dark;component/Style.xaml" />
        <ResourceDictionary Source="/Controls;component/Themes/ButtonCustomized.xaml" />
    </ResourceDictionary.MergedDictionaries>

</ResourceDictionary>

Style.xaml

<ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Color x:Key="KeyColor">#FDB800</Color>
    <Color x:Key="KeyColor2">#FBD8AB</Color>
    <SolidColorBrush x:Key="KeyColorBrush"
                     Color="{StaticResource KeyColor}" />
    <SolidColorBrush x:Key="KeyColorBrush2"
                     Color="{StaticResource KeyColor2}" />

    <Style x:Key="BorderStyle1"
           TargetType="Border">
        <Setter Property="Background"
                Value="{StaticResource KeyColorBrush}" />
    </Style>

    <Style x:Key="BorderStyle2"
           TargetType="Border">
        <Setter Property="Background"
                Value="{StaticResource KeyColorBrush2}" />
    </Style>
</ResourceDictionary>

I don't know why the explicit style doesn't are updates when change theme of the application?

Thanks for the future answers, regards.

Attached file in