Getting advanced in usercontrols

Here I am again.

So a week or 2 ago I was working on a project with my own usercontrol what has to be a button with a image and some text. I got it implemented in my program nicely and the events work like a charm but now I'd like to make it a little more eye catching.

I'm looking for a way to have a mouseenter and mouseleave event. Right now I can change the thickness of the border in my usercontrol this way:

// Button.xaml
<Border BorderThickness="{Binding BorderThick,
                                          Mode=OneWay}" 
                BorderBrush="Black"
                >

// Button.xaml.cs
private int _BorderThickness = 1;

public int BorderThick
        {
            get { return _BorderThickness; }
            set 
            { 
                _BorderThickness = value;
                NotifyPropertyChanged("BorderThick");
            }
        }

private void ControlEnter(object sender, MouseEventArgs e)
        {
            BorderThick = 5;
        }

        private void ControlLeave(object sender, MouseEventArgs e)
        {
            BorderThick = 1;
        }

Now I was wondering, is it possible to have a effect like with the normal buttons? Also, there appears to be something like triggers I found on google. With those trigger you should be able to add a storyboard (some animation if I'm right) to the control.

Let's say, I want to have my control (all of it, some overlay) turn green in 2 seconds when entering and back to normal in 2 seconds while leaving it, what would be the best way to do this? I have no experience at all with this and I'm not asking for code. I tried to search for tutorials on the internet but haven't found a good one that's working.

I did try this to change the thickness of my border but no result:

// Button.waml
 <UserControl.Style>
        <Style>
            <Style.Triggers>
                <EventTrigger RoutedEvent="Mouse.MouseEnter">
                    <EventTrigger.Actions>
                        <BeginStoryboard>
                            <Storyboard BeginTime="0:0:0.0" Storyboard.TargetName="bordertest" Storyboard.TargetProperty="BorderThickness">
                                <DoubleAnimation To="5" Duration="0:0:2.0"/>
                            </Storyboard>
                        </BeginStoryboard>
                    </EventTrigger.Actions>
                </EventTrigger>
            </Style.Triggers>
        </Style>
    </UserControl.Style>

<Border x:Name="bordertest"
BorderThickness="{Binding BorderThick,
                                          Mode=OneWay}" 
                BorderBrush="Black"
                >

I did remove the 2 events and properties in my Border.xaml.cs.