How to disable XP themes in WPF application ?

Answer 1

May I ask why custom colors are required on all controls in your application? Personally, I don't like it very much when an application does not use the look and feel of my desktop environment.

Of course, there are sometimes situations, where it might make sense to do some custom styling, but I would say these cases are rare and do not generally apply to the whole application.

Answer 2

Your best bet, to ensure a consistent behavior and appearance across operating systems, would be to re-template the TabItem control and then use a Trigger to modify a part of your new template when a TabItem is selected. Try something like the following:

<Grid>
<Grid.Resources>
  <Style x:Key="Custom">
    <Setter Property="Control.Background" Value="#FF47C7C8"/>
    <Setter Property="Control.BorderBrush" Value="#FF47C7C8"/>
    <Setter Property="Control.Foreground" Value="White"/>
  </Style>
  <Style BasedOn="{StaticResource Custom}" TargetType="TabControl"/>
  <Style TargetType="TabItem">
    <Setter Property="Foreground" Value="White"/>
    <Setter Property="Template">
      <Setter.Value>
        <ControlTemplate TargetType="{x:Type TabItem}">
          <Grid>
            <Border
              Name="Border"
              Background="#FF47C7C8"
              BorderBrush="#FFFFFF"
              BorderThickness="1,1,1,1"
              CornerRadius="2,2,0,0">
              <ContentPresenter
                x:Name="ContentSite"
                HorizontalAlignment="Center"
                Margin="12,2,12,2"
                VerticalAlignment="Center"
                ContentSource="Header"
                RecognizesAccessKey="True"/>
            </Border>
          </Grid>
          <ControlTemplate.Triggers>
            <Trigger Property="IsSelected" Value="True">
              <Setter Property="Panel.ZIndex" Value="100"/>
              <Setter TargetName="Border" Property="Background" Value="#FF47C7C8"/>
              <Setter TargetName="Border" Property="BorderThickness" Value="1,1,1,0"/>
            </Trigger>
          </ControlTemplate.Triggers>
        </ControlTemplate>
      </Setter.Value>
    </Setter>
  </Style>
</Grid.Resources>
<TabControl>
  <TabItem Header="Item 1"/>
  <TabItem Header="Item 2"/>
  <TabItem Header="Item 3"/>
  <TabItem Header="Item 4"/>
</TabControl>

Bon chance!