Changed dark mode hex values according to guidelines

Author: edongashi

MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.Card.xaml

@@ -35,7 +35,7 @@
     </ControlTemplate>
     <Style TargetType="{x:Type wpf:Card}">
         <Setter Property="Template" Value="{StaticResource CardTemplate}" />
-        <Setter Property="Background" Value="{DynamicResource MaterialDesignPaper}" />
+        <Setter Property="Background" Value="{DynamicResource MaterialDesignCardBackground}" />
         <Setter Property="VerticalAlignment" Value="Top" />
         <Setter Property="wpf:ShadowAssist.ShadowDepth" Value="Depth2" />
     </Style>

MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.Dark.xaml

@@ -6,7 +6,8 @@
     <SolidColorBrush x:Key="ValidationErrorBrush" Color="{StaticResource ValidationErrorColor}"/>
 
     <SolidColorBrush x:Key="MaterialDesignBackground" Color="#FF000000" po:Freeze="True" />
-    <SolidColorBrush x:Key="MaterialDesignPaper" Color="#FF37474f" po:Freeze="True" />
+    <SolidColorBrush x:Key="MaterialDesignPaper" Color="#FF303030" po:Freeze="True" />
+    <SolidColorBrush x:Key="MaterialDesignCardBackground" Color="#FF424242" po:Freeze="True" />
     <SolidColorBrush x:Key="MaterialDesignBody" Color="#DDFFFFFF" po:Freeze="True" />
     <SolidColorBrush x:Key="MaterialDesignBodyLight" Color="#89FFFFFF" po:Freeze="True" />
     <SolidColorBrush x:Key="MaterialDesignColumnHeader" Color="#BCFFFFFF" po:Freeze="True" /><!-- 74% -->

MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.Light.xaml

@@ -7,6 +7,7 @@
 
     <SolidColorBrush x:Key="MaterialDesignBackground" Color="#FFFFFFFF" po:Freeze="True" />
     <SolidColorBrush x:Key="MaterialDesignPaper" Color="#FFfafafa" po:Freeze="True" />
+    <SolidColorBrush x:Key="MaterialDesignCardBackground" Color="#FFFFFFFF" po:Freeze="True" />
     <SolidColorBrush x:Key="MaterialDesignBody" Color="#DD000000" po:Freeze="True" />
     <SolidColorBrush x:Key="MaterialDesignBodyLight" Color="#89000000" po:Freeze="True" />
     <SolidColorBrush x:Key="MaterialDesignColumnHeader" Color="#BC000000" po:Freeze="True" /> <!-- 74% -->