Is there a simple way to do this in Visual Studio WPF?

I have the MouseLeftButtonDown="xxxxx" and I go to the code page or the call(?) and i cant find a way to change the effect on that picture from the click.. Can anyone even just explain the process fo doing this?

Ok, im sorry I might have been a little vague in what I am after. I am very new to C#. By very new I mean under a week of learning it.

private void brawlingPic5Click(object sender, MouseButtonEventArgs e)
{
    // is there no simple way here to change the shade of a picture?
}

I was thinking that some simple line of code could apply an effect to the image or something, somthing quite standard.. Just something that would make this item stand out as having been clicked on..