title: Change Color Collapse / Expand
body: <p>is there a way to change the color under the expand/collapse bar when highlighting a procedure?
  In dark mode(twilight) I'm not able to see the beginning and the end of the subprocedure.</p>
  <p><a href="https://i.stack.imgur.com/N8TpK.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/N8TpK.png" alt="enter image description here" /></a></p>