title: Change the color of the line into the Contextual Action Bar
body: <p>I would like to change the color of the line that appears onto the contextual action bar; to be more clear I will put an image:</p>
  
  <p><img src="https://i.stack.imgur.com/g1EkX.jpg" alt="enter image description here"></p>
  
  <p>You see the Light blue line just above the white area? How could I change its color? Thanks</p>