This examples shows how to control accordion header text color

here is the complete example in flex –

<?xml version="1.0" encoding="utf-8"?>
<mx:Application
 xmlns:mx="http://www.adobe.com/2006/mxml"
 width="600"
 height="600"
 >

 <mx:Script>
 <![CDATA[
 public function setColors():void {
 myAcc.getHeaderAt(0).setStyle('color', 0xFF0000);
 myAcc.getHeaderAt(1).setStyle('color', 0x00FF00);
 myAcc.getHeaderAt(2).setStyle('color', 0x0000FF);
 }
 ]]>
 </mx:Script>

 <mx:Accordion id="myAcc" width="300" height="300" creationComplete="setColors()">
 <mx:VBox label="Container 1">
 <mx:Text text="123456"/>
 </mx:VBox>

 <mx:VBox label="Container 2">
 <mx:Text text="123456890"/>
 </mx:VBox>

 <mx:VBox label="Container 3">
 <mx:Text text="123456890 123456"/>
 </mx:VBox>
 </mx:Accordion>
</mx:Application>