If you have used the "Set back to No Borders" feature to remove the styling around the selected opening, and change your mind, then this can not be turned off as such.

However you can quickly replace the modified layout by using the shortcut key Alt (Windows)/Option (Mac) and drag the original template (while in Thumbnail view) over the layout. This will update the layout to the selected template design (in this case the original template with the style around the opening).

This shortcut/method and other helpful information can be found in the Layouts - View Modes section  on the "Thumbnail View" page in the ProSelect Reference manual (quick access under the Help menu in ProSelect).

Note: If this layout has already been ordered, then you will need to duplicate this first (remove the original order and layout) and then re-order the corrected layout (particularly for Production purposes).