Make unread messages in Notifications more prominent

When you click on the notification bell, it opens up a historical list of notifications and new unread messages have a black line on the left side of the message tile (on website desktop app). People are not understanding that line to indicate new messages and therefore getting overwhelmed with the long list of notifications. Can you make new, unread messages more visually prominent? Highlighted more prominently by border lines or color so they don't miss it?