If you add a Dynamic HTML (DHTML) (DHTML: An extension of Hypertext Markup Language (HTML) that adds multimedia, database access, and an object model that programs can use to change styles and attributes of page elements (objects) and to replace existing elements (objects) with new ones.) effect to a page element, you can show or hide a blue background and border for the effect in Design view.
To show or hide the highlighting effect, on the DHTML Effects toolbar, click Highlight Dynamic HTML Effects .
If the DHTML Effects toolbar is hidden, on the View menu, point to Toolbars, and then click DHTML Effects.