[Android] Tabs briefly display wrong background color when navigating between flyout items

src/Controls/src/Core/Compatibility/Handlers/Shell/Android/ShellItemRenderer.cs

@@ -13,6 +13,7 @@
 using Google.Android.Material.Navigation;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
+using Microsoft.Maui.Controls.Handlers.Compatibility;
 using Microsoft.Maui.Graphics;
 using AColor = Android.Graphics.Color;
 using AView = Android.Views.View;
@@ -141,6 +142,11 @@ protected virtual void SetAppearance(ShellAppearance appearance)
 				return;
 			}
 
+			// Apply background color from appearance, fallback to default if unavailable
+			if (_bottomView.Background is ColorDrawable background && appearance is IShellAppearanceElement appearanceElement)
+			{
+				background.Color = appearanceElement.EffectiveTabBarBackgroundColor?.ToPlatform() ?? ShellRenderer.DefaultBottomNavigationViewBackgroundColor.ToPlatform();
+			}
 			_appearanceSet = true;
 			_appearanceTracker.SetAppearance(_bottomView, appearance);
 		}

src/Controls/tests/TestCases.HostApp/Issues/Issue16522.xaml

@@ -0,0 +1,47 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<Shell xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+            xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+            x:Class="Maui.Controls.Sample.Issues.Issue16522"
+            TabBarBackgroundColor="#0000FF"
+            >
+  <FlyoutItem Title="Main">
+    <Tab Title="Main">
+      <ShellContent>
+        <ContentPage Title="Main">
+          <StackLayout Padding="10">
+            <Label AutomationId="Label" Text="Welcome to the Main Page!"
+                               FontSize="24"
+                               HorizontalOptions="Center" />
+            <!-- Add additional UI elements here -->
+          </StackLayout>
+        </ContentPage>
+      </ShellContent>
+    </Tab>
+
+    <Tab Title="Settings">
+      <ShellContent>
+        <ContentPage Title="Settings">
+          <StackLayout Padding="10">
+            <Label Text="Settings Page"
+                               FontSize="24"
+                               HorizontalOptions="Center" />
+            <!-- Additional UI for Settings -->
+          </StackLayout>
+        </ContentPage>
+      </ShellContent>
+    </Tab>
+  </FlyoutItem>
+
+  <FlyoutItem Title="About">
+    <ShellContent>
+      <ContentPage Title="About">
+        <StackLayout Padding="10">
+          <Label Text="About Page"
+                           FontSize="24"
+                           HorizontalOptions="Center" />
+          <!-- Additional UI for About -->
+        </StackLayout>
+      </ContentPage>
+    </ShellContent>
+  </FlyoutItem>
+</Shell>

src/Controls/tests/TestCases.HostApp/Issues/Issue16522.xaml.cs

@@ -0,0 +1,12 @@
+namespace Maui.Controls.Sample.Issues
+{
+	[Issue(IssueTracker.Github, 16522, "[Android] Tabs briefly display wrong background color when navigating between flyout items", PlatformAffected.Android)]
+	public partial class Issue16522 : Shell
+	{
+		public Issue16522()
+		{
+			InitializeComponent();
+
+		}
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue16522.cs

@@ -0,0 +1,26 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues
+{
+	public class Issue16522 : _IssuesUITest
+	{
+		public Issue16522(TestDevice device) : base(device)
+		{
+		}
+
+		public override string Issue => "[Android] Tabs briefly display wrong background color when navigating between flyout items";
+
+		[Test]
+		[Category(UITestCategories.Shell)]
+		public void ShellTabBarBackgroundColor()
+		{
+			App.WaitForElement("Label");
+			App.Tap("Settings");
+			App.Tap("Main");
+			App.WaitForElement("Label");
+			VerifyScreenshot();
+		}
+	}
+}