title: Change colour of ckeditor show blocks border
body: <p>The ckeditor editor window for the site content areas has a blue background to match the website so that the client sees a true representation of the website while adding content.</p>
  
  <p>When "show blocks" is selected the blocks border displayed is barely visible on the blue background.
  Therefore, where can the colour of the show blocks border be changed to a darker colour?</p>