diff --git a/ModernWpf/Styles/ComboBox.xaml b/ModernWpf/Styles/ComboBox.xaml
index a22aade0..39f8464c 100644
--- a/ModernWpf/Styles/ComboBox.xaml
+++ b/ModernWpf/Styles/ComboBox.xaml
@@ -443,6 +443,7 @@
                         <!-- Focused -->
                         <Trigger Property="primitives:FocusVisualHelper.ShowFocusVisual" Value="True">
                             <Setter TargetName="HighlightBackground" Property="Opacity" Value="1" />
+                            <Setter TargetName="HighlightBackground" Property="Background" Value="{DynamicResource ComboBoxBackgroundFocused}" />
                             <Setter TargetName="HighlightBackground" Property="BorderBrush" Value="{DynamicResource ComboBoxBackgroundBorderBrushFocused}" />
                             <Setter TargetName="ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundFocused}" />
                             <Setter TargetName="PlaceholderTextBlock" Property="Foreground" Value="{DynamicResource ComboBoxPlaceHolderForegroundFocused}" />
diff --git a/ModernWpf/ThemeResources/Dark.xaml b/ModernWpf/ThemeResources/Dark.xaml
index 83e98209..ba1b4959 100644
--- a/ModernWpf/ThemeResources/Dark.xaml
+++ b/ModernWpf/ThemeResources/Dark.xaml
@@ -461,6 +461,7 @@
     <m:StaticResource x:Key="ComboBoxBackgroundPressed" ResourceKey="SystemControlBackgroundListMediumBrush" />
     <m:StaticResource x:Key="ComboBoxBackgroundDisabled" ResourceKey="SystemControlBackgroundBaseLowBrush" />
     <m:StaticResource x:Key="ComboBoxBackgroundUnfocused" ResourceKey="SystemControlHighlightListAccentLowBrush" />
+    <m:StaticResource x:Key="ComboBoxBackgroundFocused" ResourceKey="ComboBoxBackgroundUnfocused" />
     <m:StaticResource x:Key="ComboBoxBackgroundBorderBrushFocused" ResourceKey="SystemControlHighlightTransparentBrush" />
     <m:StaticResource x:Key="ComboBoxBackgroundBorderBrushUnfocused" ResourceKey="SystemControlHighlightBaseMediumLowBrush" />
     <m:StaticResource x:Key="ComboBoxForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
diff --git a/ModernWpf/ThemeResources/HighContrast.xaml b/ModernWpf/ThemeResources/HighContrast.xaml
index 2e751cfa..958c3e18 100644
--- a/ModernWpf/ThemeResources/HighContrast.xaml
+++ b/ModernWpf/ThemeResources/HighContrast.xaml
@@ -461,6 +461,7 @@
     <m:StaticResource x:Key="ComboBoxBackgroundPressed" ResourceKey="SystemControlBackgroundListMediumBrush" />
     <m:StaticResource x:Key="ComboBoxBackgroundDisabled" ResourceKey="SystemControlBackgroundBaseLowBrush" />
     <m:StaticResource x:Key="ComboBoxBackgroundUnfocused" ResourceKey="SystemControlHighlightListAccentLowBrush" />
+    <m:StaticResource x:Key="ComboBoxBackgroundFocused" ResourceKey="ComboBoxBackgroundUnfocused" />
     <m:StaticResource x:Key="ComboBoxBackgroundBorderBrushFocused" ResourceKey="SystemControlHighlightTransparentBrush" />
     <m:StaticResource x:Key="ComboBoxBackgroundBorderBrushUnfocused" ResourceKey="SystemControlHighlightBaseMediumLowBrush" />
     <m:StaticResource x:Key="ComboBoxForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
diff --git a/ModernWpf/ThemeResources/Light.xaml b/ModernWpf/ThemeResources/Light.xaml
index 3a25edd3..e7cb422b 100644
--- a/ModernWpf/ThemeResources/Light.xaml
+++ b/ModernWpf/ThemeResources/Light.xaml
@@ -461,6 +461,7 @@
     <m:StaticResource x:Key="ComboBoxBackgroundPressed" ResourceKey="SystemControlBackgroundListMediumBrush" />
     <m:StaticResource x:Key="ComboBoxBackgroundDisabled" ResourceKey="SystemControlBackgroundBaseLowBrush" />
     <m:StaticResource x:Key="ComboBoxBackgroundUnfocused" ResourceKey="SystemControlHighlightListAccentLowBrush" />
+    <m:StaticResource x:Key="ComboBoxBackgroundFocused" ResourceKey="ComboBoxBackgroundUnfocused" />
     <m:StaticResource x:Key="ComboBoxBackgroundBorderBrushFocused" ResourceKey="SystemControlHighlightTransparentBrush" />
     <m:StaticResource x:Key="ComboBoxBackgroundBorderBrushUnfocused" ResourceKey="SystemControlHighlightBaseMediumLowBrush" />
     <m:StaticResource x:Key="ComboBoxForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
diff --git a/test/ModernWpfTestApp/ComboBoxPage.xaml b/test/ModernWpfTestApp/ComboBoxPage.xaml
index 9c427a74..a98498ef 100644
--- a/test/ModernWpfTestApp/ComboBoxPage.xaml
+++ b/test/ModernWpfTestApp/ComboBoxPage.xaml
@@ -9,28 +9,35 @@
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
     mc:Ignorable="d">
 
-    <StackPanel
-        Background="{DynamicResource SystemControlPageBackgroundAltHighBrush}"
-        Margin="12">
-        <TextBlock
-            Text="Sample ComboBoxes"
-            Style="{DynamicResource StandardGroupHeader}" />
-        <TextBlock Text="ComboBox:" />
+    <StackPanel Background="{ThemeResource ApplicationPageBackgroundThemeBrush}" Margin="12">
+        <TextBlock Text="Sample ComboBoxes" Style="{ThemeResource StandardGroupHeader}"/>
+        <TextBlock Text="ComboBox:"/>
         <ComboBox SelectedIndex="0">
-            <ComboBoxItem Content="Item 1" />
-            <ComboBoxItem Content="Item 2" />
-            <ComboBoxItem Content="Item 3" />
+            <ComboBoxItem Content="Item 1"/>
+            <ComboBoxItem Content="Item 2"/>
+            <ComboBoxItem Content="Item 3"/>
         </ComboBox>
 
-        <TextBlock
-            Text="ComboBox IsEditable=true:"
-            Margin="0,20,0,0" />
-        <ComboBox
-            SelectedIndex="0"
-            IsEditable="True">
-            <ComboBoxItem Content="Item 1" />
-            <ComboBoxItem Content="Item 2" />
-            <ComboBoxItem Content="Item 3" />
+        <TextBlock Text="ComboBox IsEditable=true:" Margin="0,20,0,0"/>
+        <ComboBox SelectedIndex="0" IsEditable="True">
+            <ComboBoxItem Content="Item 1"/>
+            <ComboBoxItem Content="Item 2"/>
+            <ComboBoxItem Content="Item 3"/>
         </ComboBox>
+
+        <ComboBoxEx SelectedIndex="0" Header="Focus resource lookup test">
+            <ComboBox.Resources>
+                <ResourceDictionary>
+                    <SolidColorBrush x:Key="ComboBoxBackgroundFocused" Color="Green"/>
+                    <SolidColorBrush x:Key="ComboBoxBackgroundUnfocused" Color="Red"/>
+                    <SolidColorBrush x:Key="ComboBoxBackgroundBorderBrushFocused" Color="Blue"/>
+                    <SolidColorBrush x:Key="ComboBoxBackgroundBorderBrushUnfocused" Color="Yellow"/>
+                </ResourceDictionary>
+            </ComboBox.Resources>
+            <ComboBoxItem Content="Item 1"/>
+            <ComboBoxItem Content="Item 2"/>
+            <ComboBoxItem Content="Item 3"/>
+        </ComboBoxEx>
+
     </StackPanel>
 </local:TestPage>