<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2007/12/19/alternating-item-colors-in-combobox-dropdown/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="top"
        backgroundColor="white" viewSourceURL="srcview/index.html">

    <mx:ComboBox id="comboBox"
            alternatingItemColors="['red', 0x00FF00, '#0000FF']">
        <mx:dataProvider>
            <mx:Array>
                <mx:Object label="One" />
                <mx:Object label="Two" />
                <mx:Object label="Three" />
                <mx:Object label="Four" />
                <mx:Object label="Five" />
                <mx:Object label="Six" />
                <mx:Object label="Seven" />
            </mx:Array>
        </mx:dataProvider>
    </mx:ComboBox>

</mx:Application>