Remove relative source

Author: jherbert

MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.Expander.xaml

@@ -70,7 +70,7 @@
                             </VisualStateGroup>
                         </VisualStateManager.VisualStateGroups>
                         <wpf:PackIcon Kind="ChevronDown" Opacity=".38" x:Name="ExpandPath" RenderTransformOrigin="0.5,0.5"
-                                      Height="24" Width="24" Foreground="{Binding RelativeSource={RelativeSource AncestorType={x:Type Expander}}, Path=Foreground}">
+                                      Height="24" Width="24" Foreground="{TemplateBinding Foreground}">
                             <wpf:PackIcon.RenderTransform>
                                 <TransformGroup>
                                     <ScaleTransform/>