title: javaFX styling TableView
body: <p>I'm trying to style my table.view.  How can I style this blue elements in tableview when the column is drag ? 
  <a href="https://i.stack.imgur.com/1g05e.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1g05e.png" alt="enter image description here"></a></p>