Wrap your link with .link-overlay and add a child element with .link-overlay-bg to get the overlay effect.
Change the background color by adding a modifier class: .link-overlay-bg-primary, .link-overlay-bg-secondary, .link-overlay-bg-success, .link-overlay-bg-info, .link-overlay-bg-warning, .link-overlay-bg-danger, or .link-overlay-bg-purple.