HalidCisse

<!-- Flat ComboBox -->
  <SolidColorBrush x:Key="ComboBoxNormalBorderBrush" Color="#e3e9ef" />
  <SolidColorBrush x:Key="ComboBoxNormalBackgroundBrush" Color="#fff" />
  <SolidColorBrush x:Key="ComboBoxDisabledForegroundBrush" Color="#888" />
  <SolidColorBrush x:Key="ComboBoxDisabledBackgroundBrush" Color="#eee" />
  <SolidColorBrush x:Key="ComboBoxDisabledBorderBrush" Color="#888" />

  <ControlTemplate TargetType="ToggleButton" x:Key="ComboBoxToggleButtonTemplate">
    <Grid>
      <Grid.ColumnDefinitions>

HalidCisse

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Style
        x:Key="ButtonFocusVisual">
        <Setter
            Property="Control.Template">
            <Setter.Value>
                <ControlTemplate>
                    <Rectangle Margin="2" SnapsToDevicePixels="true" Stroke="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}" StrokeThickness="1" StrokeDashArray="1 2" />
                </ControlTemplate>