Fluent: Replace ErrorBrush resources

src/Avalonia.Themes.Fluent/ButtonSpinner.xaml

@@ -8,7 +8,11 @@
       <StackPanel Spacing="20">
         <ButtonSpinner ButtonSpinnerLocation="Right"
                        Content="Right disabled inline spinner"
-                       AllowSpin="False" />
+                       AllowSpin="False">
+          <DataValidationErrors.Error>
+            <sys:Exception />
+          </DataValidationErrors.Error>
+        </ButtonSpinner>
         <ButtonSpinner ButtonSpinnerLocation="Left"
                        Content="Left spinner" />
         <ButtonSpinner ShowButtonSpinner="False"
@@ -133,7 +137,7 @@
 
   <!--  Error state  -->
   <Style Selector="ButtonSpinner:error">
-    <Setter Property="BorderBrush" Value="{DynamicResource ErrorBrush}" />
+    <Setter Property="BorderBrush" Value="{DynamicResource SystemErrorTextColor}" />
   </Style>
 
 </Styles>

src/Avalonia.Themes.Fluent/DataValidationErrors.xaml

@@ -1,5 +1,16 @@
 <Style xmlns="https://github.com/avaloniaui" 
-       Selector="DataValidationErrors">
+       Selector="DataValidationErrors"
+       xmlns:sys="clr-namespace:System;assembly=netstandard">
+  <Design.PreviewWith>
+    <Border Padding="20"> 
+      <TextBox Text="Sample">
+        <DataValidationErrors.Error>
+          <sys:Exception/> 
+        </DataValidationErrors.Error>
+      </TextBox>
+    </Border>
+  </Design.PreviewWith>
+    
   <Setter Property="Template">
     <ControlTemplate>
       <DockPanel LastChildFill="True">
@@ -24,14 +35,13 @@
               Background="Transparent">
         <Canvas.Styles>
           <Style Selector="ToolTip">
-            <Setter Property="Background" Value="{DynamicResource ErrorLowBrush}"/>
-            <Setter Property="BorderBrush" Value="{DynamicResource ErrorBrush}"/>
+            <Setter Property="BorderBrush" Value="{DynamicResource SystemControlErrorTextForegroundBrush}"/>
           </Style>
         </Canvas.Styles>
         <ToolTip.Tip>
           <ItemsControl Items="{Binding}"/>
         </ToolTip.Tip>
-        <Path Data="M14,7 A7,7 0 0,0 0,7 M0,7 A7,7 0 1,0 14,7 M7,3l0,5 M7,9l0,2" Stroke="{DynamicResource ErrorBrush}" StrokeThickness="2"/>
+        <Path Data="M14,7 A7,7 0 0,0 0,7 M0,7 A7,7 0 1,0 14,7 M7,3l0,5 M7,9l0,2" Stroke="{DynamicResource SystemControlErrorTextForegroundBrush}" StrokeThickness="2"/>
       </Canvas>
     </DataTemplate>
   </Setter>

src/Avalonia.Themes.Fluent/TextBox.xaml

@@ -1,4 +1,13 @@
 <Styles xmlns="https://github.com/avaloniaui" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+  <Design.PreviewWith>
+    <Border Padding="20">
+      <TextBox Text="Sample"
+               FontSize="20"
+               Width="100"
+               TextAlignment="Center"/>
+    </Border>
+  </Design.PreviewWith>
+  
   <Styles.Resources>
     <Thickness x:Key="TextBoxTopHeaderMargin">0,0,0,4</Thickness>
   </Styles.Resources>
@@ -42,7 +51,7 @@
               <DockPanel>
                 <TextBlock Name="floatingWatermark"
                            Foreground="{DynamicResource SystemAccentColor}"
-                           FontSize="{DynamicResource FontSizeSmall}"
+                           FontSize="{TemplateBinding FontSize}"
                            Text="{TemplateBinding Watermark}"
                            DockPanel.Dock="Top">
                   <TextBlock.IsVisible>
@@ -136,7 +145,7 @@
 
 
   <Style Selector="TextBox:error /template/ Border#border">
-    <Setter Property="BorderBrush" Value="{DynamicResource ErrorBrush}"/>
+    <Setter Property="BorderBrush" Value="{DynamicResource SystemControlErrorTextForegroundBrush}"/>
   </Style>
 
   <Style Selector="TextBox /template/ DockPanel">