Change Application backgroundGradientColors in Flex 3

 <?xml version="1.0" encoding="utf-8"?>  
 <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">  
 <mx:Script>  
      <![CDATA[  
           private function changeGradientColors():void  
           {  
                Application.application.setStyle('backgroundGradientColors', [colorPicker.selectedColor, colorPicker2.selectedColor]);  
                Application.application.setStyle('backgroundGradientColors', [colorPicker.selectedColor, colorPicker2.selectedColor]);  
           }  
      ]]>  
 </mx:Script>  
      <mx:ColorPicker id="colorPicker" change="changeGradientColors()" x="76" y="52"/>  
      <mx:ColorPicker id="colorPicker2" change="changeGradientColors()" x="76" y="82"/>  
 </mx:Application>