Добавление кнопок в run-time

_buttons[i].Click += (sender, e) =>
{
    var button = (Button)sender;
    button.Background = new SolidColorBrush();
    var animation = new ColorAnimation(
        Colors.Black,
        Colors.Orange,
        new Duration(TimeSpan.FromMilliseconds(100)));
    animation.AutoReverse = true;
    animation.RepeatBehavior = new RepeatBehavior(5);
    button.Background.BeginAnimation(SolidColorBrush.ColorProperty, animation);
};

 private void Blink()
        {
            Background = new SolidColorBrush();
            var animation = new ColorAnimation(
                Colors.Black,
                Colors.Green,
                new Duration(TimeSpan.FromMilliseconds(TimeToSleep)))
                {AutoReverse = true, RepeatBehavior = new RepeatBehavior(N)};
            Background.BeginAnimation(SolidColorBrush.ColorProperty, animation);
        }

animation.Completed += (sender, args) => Background = Brushes.Green;

Background = new SolidColorBrush(Colors.Green);

animation.FillBehavior = FillBehavior.Stop;