<Style TargetType="{x:Type Button}" x:Key="Awsome">
            <Style.Triggers>
                <EventTrigger RoutedEvent="MouseEnter">
                    <BeginStoryboard>
                        <Storyboard>

                            <ColorAnimation Storyboard.TargetProperty="Background.(SolidColorBrush.Color)"
                                            From="Aqua" AutoReverse="True"
                                            RepeatBehavior="Forever"
                                            To="Blue" Duration="0:0:.9">
                            </ColorAnimation>

                            <DoubleAnimation Storyboard.TargetProperty="Width"
                                             From="100" RepeatBehavior="Forever"
                                             To="200" Duration="0:0:.3" AutoReverse="True"/>
                        </Storyboard>
                    </BeginStoryboard>
                </EventTrigger>
            </Style.Triggers>
        </Style>