Use this snippet to remove the overlay for all rows:
.page-template-page_widgetized section .row-overlay { display: none; }
To remove the overlay just for a specific row, use and adapt this snippet:
#yoursectionid .row-overlay { display: none; }
Tip: Set an ID for your row from the widget styling options found in Customize > Widgets, then replace yoursectionid with your actual ID.
INFO: This is a CSS snippet. If you don’t have a child theme or don’t know how to use one, we recommend that you add this snippet in Customize > Additional CSS.