<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2009/02/05/setting-the-background-color-on-a-fxbutton-control-in-flex-gumbo/ -->
<s:Application name="Spark_Button_baseColor_test"
        xmlns:fx="http://ns.adobe.com/mxml/2009"
        xmlns:s="library://ns.adobe.com/flex/spark"
        xmlns:mx="library://ns.adobe.com/flex/halo" viewSourceURL="srcview/index.html">

    <mx:ApplicationControlBar width="100%" cornerRadius="0">
        <mx:Form styleName="plain">
            <mx:FormItem label="baseColor:">
                <mx:ColorPicker id="colorPicker"
                        selectedColor="#CCCCCC" />
            </mx:FormItem>
        </mx:Form>
    </mx:ApplicationControlBar>

    <s:Button id="btn"
            label="Spark Button"
            baseColor="{colorPicker.selectedColor}"
            horizontalCenter="0" verticalCenter="0" />

</s:Application>