Use custom themes for tab border

The border for the blue theme is too dark in my opinion.

Author: donokuda

src/GitHub.VisualStudio/Styles/ThemeBlue.xaml

@@ -42,4 +42,6 @@
 
   <SolidColorBrush x:Key="GitHubComboBoxBackgroundBrush" Color="#FFF6F6F6" />
   <SolidColorBrush x:Key="GitHubComboBoxBorderBrush" Color="#FFCCCEDC" />
+
+  <SolidColorBrush x:Key="GitHubTabItemSelectedBorder" Color="#FFD0D7E4" />
 </ResourceDictionary>

src/GitHub.VisualStudio/Styles/ThemeDark.xaml

@@ -42,4 +42,6 @@
 
   <SolidColorBrush x:Key="GitHubComboBoxBackgroundBrush" Color="#FF1B1B1C" />
   <SolidColorBrush x:Key="GitHubComboBoxBorderBrush" Color="#FF434346" />
+
+  <SolidColorBrush x:Key="GitHubTabItemSelectedBorder" Color="#FF3F3F46" />
 </ResourceDictionary>

src/GitHub.VisualStudio/Styles/ThemeDesignTime.xaml

@@ -4,11 +4,10 @@
   xmlns:PresentationOptions="http://schemas.microsoft.com/winfx/2006/xaml/presentation/options">
 
   <ResourceDictionary.MergedDictionaries>
-    <ResourceDictionary Source="pack://application:,,,/GitHub.VisualStudio;component/Styles/ThemeDark.xaml" />
+    <ResourceDictionary Source="pack://application:,,,/GitHub.VisualStudio;component/Styles/ThemeBlue.xaml" />
   </ResourceDictionary.MergedDictionaries>
 
   <!-- Design time colors taken from the VS dark theme
-  -->
   <SolidColorBrush x:Key="GitHubVsToolWindowText" Color="#FFFFFFFF" />
   <SolidColorBrush x:Key="GitHubVsToolWindowBackground" Color="#FF252526" />
   <SolidColorBrush x:Key="GitHubVsGrayText" Color="#FF999999" />
@@ -17,6 +16,7 @@
   <SolidColorBrush x:Key="GitHubVsSearchBoxBackground" Color="#FF333337" />
   <SolidColorBrush x:Key="GitHubVsWindowText" Color="#FFF1F1F1" />
   <SolidColorBrush x:Key="GitHubVsBrandedUIBorder" Color="#FF3F3F46" />
+  -->
 
   <!-- Design time colors taken from the VS light theme
   <SolidColorBrush x:Key="GitHubVsToolWindowText" Color="#FF1E1E1E" />
@@ -31,6 +31,7 @@
   -->
 
   <!-- Design time colors taken from the VS blue theme
+  -->
   <SolidColorBrush x:Key="GitHubVsToolWindowText" Color="#FF000000" />
   <SolidColorBrush x:Key="GitHubVsToolWindowBackground" Color="#FFFFFFFF" />
   <SolidColorBrush x:Key="GitHubVsGrayText" Color="#FF6d6d6d" />
@@ -40,5 +41,4 @@
   <SolidColorBrush x:Key="GitHubVsWindowText" Color="#FF000000" />
   <SolidColorBrush x:Key="GitHubVsBrandedUIBorder" Color="#FF8591A2" />
   <SolidColorBrush x:Key="GitHubVsBrandedUIBackground" Color="#FFFFFFFF" />
-  -->
 </ResourceDictionary>

src/GitHub.VisualStudio/Styles/ThemeLight.xaml

@@ -29,6 +29,7 @@
   <SolidColorBrush x:Key="GitHubButtonForegroundBrush" Color="#FF666666" />
   <SolidColorBrush x:Key="GitHubButtonBorderBrush" Color="#FFCACACA" />
   <SolidColorBrush x:Key="GitHubButtonBorderMouseOverBrush" Color="#FFCACACA" />
+
   <SolidColorBrush x:Key="GitHubButtonBorderPressedBrush" Color="#FFBFBFBF" />
 
   <SolidColorBrush x:Key="GitHubPrimaryButtonBackgroundBrush" Color="#FF8BD26B" />
@@ -42,4 +43,6 @@
 
   <SolidColorBrush x:Key="GitHubComboBoxBackgroundBrush" Color="#FFF6F6F6" />
   <SolidColorBrush x:Key="GitHubComboBoxBorderBrush" Color="#FFCCCEDC" />
+
+  <SolidColorBrush x:Key="GitHubTabItemSelectedBorder" Color="#FFCCCEBD" />
 </ResourceDictionary>

src/GitHub.VisualStudio/UI/Views/PullRequestCreationView.xaml

@@ -35,7 +35,7 @@
                 <Setter Property="HorizontalContentAlignment" Value="Center"/>
                 <Setter Property="VerticalContentAlignment" Value="Center"/>
                 <Setter Property="Background" Value="{DynamicResource GitHubVsToolWindowBackground}"/>
-                <Setter Property="BorderBrush" Value="{DynamicResource GitHubVsBrandedUIBorder}"/>
+                <Setter Property="BorderBrush" Value="{DynamicResource GitHubTabItemSelectedBorder}"/>
                 <Setter Property="BorderThickness" Value="0,1,0,0"/>
                 <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
                 <Setter Property="Template">
@@ -117,7 +117,7 @@
                             <ControlTemplate.Triggers>
                                 <Trigger Property="IsSelected" Value="True">
                                     <Setter TargetName="Border" Property="Background" Value="{DynamicResource GitHubVsToolWindowBackground}" />
-                                    <Setter TargetName="Border" Property="BorderBrush" Value="{DynamicResource GitHubVsBrandedUIBorder}" />
+                                    <Setter TargetName="Border" Property="BorderBrush" Value="{DynamicResource GitHubTabItemSelectedBorder}" />
                                     <Setter TargetName="Border" Property="BorderThickness" Value="1,1,1,0" />
                                 </Trigger>
 
@@ -690,7 +690,6 @@
                                        Foreground="{DynamicResource GitHubVsGrayText}"/>
                         </Grid>
                     </ListViewItem>
-
                 </ListView>
             </TabItem>