Flex: line chart backgroundelement color (use grid as an example)

<? XML version = "1.0" ?>  
<! -- Charts/basicline. mxml -->  
< MX: Application Xmlns: MX = "Http://www.adobe.com/2006/mxml" Width = "100%"  
Height = "100%" >  
< MX: script > <! [CDATA [  
Import MX. Collections. arraycollection;
[Bindable]
Public var expenses: arraycollection = new arraycollection ([
{Month: "Jan", profit: 2000, expenses: 1500, amount: 450 },
{Month: "FEB", profit: 1000, expenses: 200, amount: 600 },
{Month: "Mar", profit: 1500, expenses: 500, amount: 300}
]);
]> </ MX: script >  
< MX: Panel Title = "Line chart" Width = "100%" Height = "100%" >  
< MX: linechart ID = "MyChart" Dataprovider = "{Expenses }"  
Showdatatips = "True" Width = "100%" Height = "100%" >

< MX: backgroundelements >  
< MX: Grid Height = "100%" Width = "100%" Verticalgap = "0" >  
< MX: gridrow Height = "20%" Width = "100%" >  
< MX: griditem Height = "100%" Width = "100%" >  
< MX: canvas Height = "100%" Width = "100%" Alpha = "0.7"  
Backgroundcolor = "#1dae00"   />  
</ MX: griditem >  
</ MX: gridrow >  
< MX: gridrow Height = "20%" Width = "100%" >  
< MX: griditem Height = "100%" Width = "100%" >  
< MX: canvas Height = "100%" Width = "100%" Alpha = "0.7"  
Backgroundcolor = "# Ffa800"   />  
</ MX: griditem >  
</ MX: gridrow >  
< MX: gridrow Height = "20%" Width = "100%" >  
< MX: griditem Height = "100%" Width = "100%" >  
< MX: canvas Height = "100%" Width = "100%" Alpha = "0.7"  
Backgroundcolor = "# Ff0000"   />  
</ MX: griditem >  
</ MX: gridrow >  
< MX: gridrow Height = "20%" Width = "100%" >  
< MX: griditem Height = "100%" Width = "100%" >  
< MX: canvas Height = "100%" Width = "100%" Alpha = "0.7"  
Backgroundcolor = "# D65f48"   />  
</ MX: griditem >  
</ MX: gridrow >  
< MX: gridrow Height = "20%" Width = "100%" >  
< MX: griditem Height = "100%" Width = "100%" >  
< MX: canvas Height = "100%" Width = "100%" Alpha = "0.7"  
Backgroundcolor = "# Cfc505"   />  
</ MX: griditem >  
</ MX: gridrow >  
</ MX: Grid >  
</ MX: backgroundelements >  

< MX: horizontalaxis >  
< MX: categoryaxis Dataprovider = "{Expenses }"  
Categoryfield = "Month"   />  
</ MX: horizontalaxis >  
< MX: Series >  
< MX: lineseries Yfield = "Profit" Displayname = "Profit"   />  
< MX: lineseries Yfield = "Expenses" Displayname = "Expenses"   />  
</ MX: Series >  
</ MX: linechart >  
< MX: Legend Dataprovider = "{MyChart }" />  
</ MX: Panel >  
</ MX: Application >