Revert "refactor how colour schemes are loaded."

This reverts commit 317684b70a.

samples/ControlCatalog/App.xaml.cs

@@ -30,24 +30,18 @@ namespace ControlCatalog
         {
             new StyleInclude(new Uri("avares://ControlCatalog/Styles"))
             {
-                Source = new Uri("avares://Avalonia.Themes.Fluent/Accents/BaseDarkColors.xaml")
-            }
+                Source = new Uri("avares://Avalonia.Themes.Fluent/FluentDark.xaml")
+            },
+            DataGridFluent
         };
 
         public static Styles FluentLight = new Styles
-        {
-            new StyleInclude(new Uri("avares://ControlCatalog/Styles"))
-            {
-                Source = new Uri("avares://Avalonia.Themes.Fluent/Accents/BaseLightColors.xaml")
-            }
-        };
-        
-        public static Styles FluentLightTheme = new Styles
         {
             new StyleInclude(new Uri("avares://ControlCatalog/Styles"))
             {
                 Source = new Uri("avares://Avalonia.Themes.Fluent/FluentLight.xaml")
-            }
+            },
+            DataGridFluent
         };
 
         public static Styles DefaultLight = new Styles
@@ -103,7 +97,6 @@ namespace ControlCatalog
         public override void Initialize()
         {
             Styles.Insert(0, FluentLight);
-            Styles.Insert(1, FluentLightTheme);
 
             AvaloniaXamlLoader.Load(this);
         }

src/Avalonia.Themes.Fluent/Accents/BaseDark.xaml

@@ -1,7 +1,7 @@
-<Styles xmlns="https://github.com/avaloniaui"
+<Style xmlns="https://github.com/avaloniaui"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:sys="clr-namespace:System;assembly=netstandard">
-  <Styles.Resources>
+  <Style.Resources>
     <SolidColorBrush x:Key="SystemControlBackgroundAccentBrush" Color="{DynamicResource SystemAccentColor}" />
     <SolidColorBrush x:Key="SystemControlBackgroundAltHighBrush" Color="{StaticResource SystemAltHighColor}" />
     <SolidColorBrush x:Key="SystemControlBackgroundAltMediumHighBrush" Color="{StaticResource SystemAltMediumHighColor}" />
@@ -145,5 +145,5 @@
 
     <!-- Moved from Menu.xaml -->
     <Thickness x:Key="MenuBarItemPadding">12,0,12,0</Thickness> 
-  </Styles.Resources>
-</Styles>
+  </Style.Resources>
+</Style>

src/Avalonia.Themes.Fluent/Accents/BaseLight.xaml

@@ -1,7 +1,7 @@
-<Styles xmlns="https://github.com/avaloniaui"
+<Style xmlns="https://github.com/avaloniaui"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:sys="clr-namespace:System;assembly=netstandard">
-  <Styles.Resources>
+  <Style.Resources>
     <SolidColorBrush x:Key="SystemControlBackgroundAccentBrush" Color="{DynamicResource SystemAccentColor}" />
     <SolidColorBrush x:Key="SystemControlBackgroundAltHighBrush" Color="{StaticResource SystemAltHighColor}" />
     <SolidColorBrush x:Key="SystemControlBackgroundAltMediumHighBrush" Color="{StaticResource SystemAltMediumHighColor}" />
@@ -148,5 +148,5 @@
 
     <!-- Moved from Menu.xaml -->
     <Thickness x:Key="MenuBarItemPadding">12,0,12,0</Thickness>
-  </Styles.Resources>
-</Styles>
+  </Style.Resources>
+</Style>

src/Avalonia.Themes.Fluent/FluentDark.xaml

@@ -3,6 +3,7 @@
        xmlns:sys="clr-namespace:System;assembly=netstandard">
   <StyleInclude Source="avares://Avalonia.Themes.Fluent/Accents/AccentColors.xaml" />
   <StyleInclude Source="avares://Avalonia.Themes.Fluent/Accents/BaseDark.xaml" />
+  <StyleInclude Source="avares://Avalonia.Themes.Fluent/Accents/BaseDarkColors.xaml" />
   <StyleInclude Source="avares://Avalonia.Themes.Fluent/Accents/Base.xaml" />
   <StyleInclude Source="avares://Avalonia.Themes.Fluent/Accents/FluentControlResourcesDark.xaml" />
   <StyleInclude Source="avares://Avalonia.Themes.Fluent/Controls/FluentControls.xaml" />

src/Avalonia.Themes.Fluent/FluentLight.xaml

@@ -2,7 +2,8 @@
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:sys="clr-namespace:System;assembly=netstandard">
   <StyleInclude Source="avares://Avalonia.Themes.Fluent/Accents/AccentColors.xaml" />
-  <StyleInclude Source="avares://Avalonia.Themes.Fluent/Accents/BaseLight.xaml" />  
+  <StyleInclude Source="avares://Avalonia.Themes.Fluent/Accents/BaseLight.xaml" />
+  <StyleInclude Source="avares://Avalonia.Themes.Fluent/Accents/BaseLightColors.xaml" />
   <StyleInclude Source="avares://Avalonia.Themes.Fluent/Accents/Base.xaml" />  
   <StyleInclude Source="avares://Avalonia.Themes.Fluent/Accents/FluentControlResourcesLight.xaml" />
   <StyleInclude Source="avares://Avalonia.Themes.Fluent/Controls/FluentControls.xaml" />