[Pharo-dev] Starting with Roassal 2

Ok here comes the first question how I change the background color of RTView ? also when I do this v := RTView new. shape := RTEllipse new size: 20; color: Color red. shape := shape + RTLabel. es := shape elementOn:'hello'. v add: es. line := RTDirectedLine new pointsFrom: 20@20 To: 30@30. es2 := line element.v add: es2. es @ RTDraggable. v @ RTDraggableView . v open. I am getting an error MNU Array >> element why ?