Use Item for transparent rectangles

resources/qml/delegates/FileMessage.qml

 import QtQuick 2.6
 import QtQuick.Layouts 1.2
 
-Rectangle {
-	color: "transparent"
+Item {
 	height: row.height + 24
 	width: parent ? parent.width : undefined
 

resources/qml/delegates/Reply.qml

@@ -3,7 +3,7 @@ import QtQuick.Controls 2.3
 import QtQuick.Layouts 1.2
 import QtQuick.Window 2.2
 
-Rectangle {
+Item {
 	id: replyComponent
 
 	property alias modelData: reply.modelData
@@ -54,8 +54,6 @@ Rectangle {
 		}
 	}
 
-	color: "transparent"
-
 	Rectangle {
 		id: backgroundItem
 		z: -1