Fix merged dictionaries ordering

src/Avalonia.Themes.Fluent/FluentTheme.xaml

@@ -6,15 +6,15 @@
   <Styles.Resources>
     <ResourceDictionary>
       <ResourceDictionary.MergedDictionaries>
-        <!-- Resources and brushes will be merged into current dictionary for slightly better performance and possible optimizations -->
-        <MergeResourceInclude Source="/Accents/BaseResources.xaml" />
-        <MergeResourceInclude Source="/Accents/FluentControlResources.xaml" />
-
         <!-- Keep custom palettes higher priority than default BaseColorsPalette and SystemAccentColors
              As that's an only place for user to redefine palette in a good way -->
-        <fluent:ColorPaletteResourcesCollection />
-        <accents:SystemAccentColors />
         <ResourceInclude Source="/Accents/BaseColorsPalette.xaml" />
+        <accents:SystemAccentColors />
+        <fluent:ColorPaletteResourcesCollection />
+
+        <!-- Resources and brushes will be merged into current dictionary for slightly better performance and possible optimizations -->
+        <MergeResourceInclude Source="/Accents/BaseResources.xaml" />
+        <MergeResourceInclude Source="/Accents/FluentControlResources.xaml" />
       </ResourceDictionary.MergedDictionaries>
       
       <!-- These are not part of MergedDictionaries so we can add or remove them easier -->