You can extend Universal Theme with the following JavaScript based APIs.
apex.theme42.configureSuccessMessages Configure the display behavior of success messages. You can use this API to programmatically determine how long the success message is displayed before automatically dismissing itself.
apex.theme42.configureSuccessMessages
apex.jQuery( document ).ready( function() { apex.theme42.configureSuccessMessages({ autoDismiss: true, duration: 5000 // Optional. Default value is 3000 }); });