ForegroundAnimPage

ForegroundAnimPage.xaml

<Page
    x:Class="GTWin8.Ui.Drafts.ForegroundAnimPage"
    IsTabStop="false"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:GTWin8.Ui.Drafts"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d">

    <Page.Resources>
        <Storyboard x:Name="TheAnimation">
            <ObjectAnimationUsingKeyFrames 
                    Storyboard.TargetName="TheTextBox"
                    Storyboard.TargetProperty="(Foreground).(SolidColorBrush.Color)">
                <DiscreteObjectKeyFrame KeyTime="0" Value="#FF0000"/>
            </ObjectAnimationUsingKeyFrames>          
        </Storyboard>        
    </Page.Resources>
    
    <Grid Background="{StaticResource ApplicationPageBackgroundThemeBrush}">
        <TextBox x:Name="TheTextBox" HorizontalAlignment="Left" Margin="11,57,0,0" 
    		TextWrapping="Wrap" 
            Text="Some text" VerticalAlignment="Top" 
    		BorderBrush="White" 
            Background="#FFBBBB" IsReadOnly="True"/>
        <Button x:Name="TheButton" Content="Animate" Click="Button_Click_1" HorizontalAlignment="Left" Margin="10,10,0,0" VerticalAlignment="Top"/>
    </Grid>
</Page>

ForegroundAnimPage.xaml.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Media.Animation;
using Windows.UI.Xaml.Navigation;

// The Blank Page item template is documented at http://go.microsoft.com/fwlink/?LinkId=234238

namespace GTWin8.Ui.Drafts
{
    /// <summary>
    /// An empty page that can be used on its own or navigated to within a Frame.
    /// </summary>
    public sealed partial class ForegroundAnimPage : Page
    {
        public ForegroundAnimPage()
        {
            this.InitializeComponent();
            TheAnimation.Completed += TheAnimation_Completed;
        }

        /// <summary>
        /// Invoked when this page is about to be displayed in a Frame.
        /// </summary>
        /// <param name="e">Event data that describes how this page was reached.  The Parameter
        /// property is typically used to configure the page.</param>
        protected override void OnNavigatedTo(NavigationEventArgs e)
        {
        }

        private void Button_Click_1(object sender, RoutedEventArgs e)
        {
            Debug.WriteLine("Color before animation: " + ((SolidColorBrush)TheTextBox.Foreground).Color);
            TheAnimation.Begin();
        }

        void TheAnimation_Completed(object sender, object e)
        {
            Debug.WriteLine(" Color after animation: " + ((SolidColorBrush)TheTextBox.Foreground).Color);
        }
    }
}