When adding or modifying a link on the front-office side, a new warning message is displayed to the user as soon as the link entered begins with neither http nor https.
The CSS class associated with this text is "add-links-dialog-url-warning", to be added to your CSS files to customize the graphic rendering.
Example:
.add-links-dialog-url-warning { margin-top: 5px; color: #ffae01; }
.add-links-dialog-url-warning { margin-top: 5px; color: #ffae01; }
.add-links-dialog-url-warning { margin-top: 5px; color: #ffae01; }