[Windows] Fix Span Foreground property

src/Controls/src/Core/Platform/Windows/Extensions/FormattedStringExtensions.cs

@@ -79,6 +79,7 @@ public static void UpdateInlines(
 						Foreground = textColor?.ToPlatform(),
 					};
 
+					run.Foreground = textColor?.ToPlatform();
 					textBlock.TextHighlighters.Add(textHighlighter);
 				}
 

src/Controls/tests/TestCases.HostApp/Issues/Issue23488.xaml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             x:Class="Maui.Controls.Sample.Issues.Issue23488">
+
+  <StackLayout HorizontalOptions="Center"
+               VerticalOptions="Center">
+    <Label Text="hyperlink"
+           TextColor="Blue"
+           TextDecorations="Underline" />
+    <Label AutomationId="WaitForLabelControl">
+      <Label.FormattedText>
+        <FormattedString>
+          <Span Text="hyperlink" 
+                TextColor="Blue"
+                TextDecorations="Underline" />
+        </FormattedString>
+      </Label.FormattedText>
+    </Label>
+  </StackLayout>
+
+</ContentPage>

src/Controls/tests/TestCases.HostApp/Issues/Issue23488.xaml.cs

@@ -0,0 +1,12 @@
+namespace Maui.Controls.Sample.Issues
+{
+	[XamlCompilation(XamlCompilationOptions.Compile)]
+	[Issue(IssueTracker.Github, 23488, "Span text-decoration is incorrect whereas the Label behaves properly", PlatformAffected.UWP)]
+	public partial class Issue23488 : ContentPage
+    {
+        public Issue23488()
+        {
+            InitializeComponent();
+        }
+    }
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue23488.cs

@@ -0,0 +1,25 @@
+#if !MACCATALYST
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues
+{
+    public class Issue23488 : _IssuesUITest
+    {
+		public Issue23488(TestDevice device): base(device)
+		{
+		}
+
+		public override string Issue => "Span text-decoration is incorrect whereas the Label behaves properly";
+
+		[Test]
+		[Category(UITestCategories.Label)]
+		public void LabelHyperlinkUnderlineColor()
+		{
+			App.WaitForElement("WaitForLabelControl");
+			VerifyScreenshot();
+		}
+	}
+}
+#endif