Updated the review suggestions.

Author: DhanarajRajendran

maui/samples/Gallery/Samples/CircularChart/Interaction/Tooltip.xaml

@@ -19,7 +19,7 @@
             <chart:SfCircularChart.Resources>
                 <ResourceDictionary>
                     <local:TooltipValueConverter x:Key="valueConverter"/>
-                    <DataTemplate x:Key="template1">
+                    <DataTemplate x:Key="template1" x:DataType="chart:TooltipInfo">
                         <StackLayout Padding="0">
                             <StackLayout Orientation="Horizontal"  VerticalOptions="Fill" Spacing="0" Padding="0" Margin="0">
                                 <Label Text="{Binding Item, Converter={StaticResource valueConverter}, ConverterParameter='Name'}" VerticalTextAlignment="Center" HorizontalOptions="Start" TextColor="{AppThemeBinding Default={StaticResource ContentBackground}}" FontAttributes="Bold" FontFamily="Helvetica" FontSize="14" Margin="2,0,2,0" />

maui/samples/Gallery/Samples/CircularChart/RadialBar/RadialBarChart.xaml.cs

@@ -78,8 +78,16 @@ private void trackFill_SelectedIndexChanged(object sender, EventArgs e)
 			{
 				case 0:
 					{
-						radialBarSeries.TrackFill = new SolidColorBrush(Color.FromRgba(0, 0, 0, 0.08));
-						break;
+						if (Application.Current?.RequestedTheme == AppTheme.Dark)
+						{
+							radialBarSeries.TrackFill = new SolidColorBrush(Color.FromRgba("#36323B"));
+							break;
+						}
+						else
+						{
+							radialBarSeries.TrackFill = new SolidColorBrush(Color.FromRgba(0, 0, 0, 0.08));
+							break;
+						}
 					}
 				case 1:
 					{