<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/08/17/changing-the-background-color-of-a-disabled-textarea-control-in-flex/ -->
<mx:Application name="TextArea_backgroundDisabledColor_test"
        xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">

    <mx:String id="lorem" source="lorem.txt" />

    <mx:Style>
        TextArea {
            backgroundDisabledColor: haloSilver;
        }
    </mx:Style>

    <mx:ApplicationControlBar dock="true">
        <mx:Form styleName="plain">
            <mx:FormItem label="enabled:">
                <mx:CheckBox id="checkBox"
                        selected="true" />
            </mx:FormItem>
        </mx:Form>
    </mx:ApplicationControlBar>

    <mx:TextArea id="textArea"
            text="{lorem}"
            enabled="{checkBox.selected}"
            width="100%"
            height="100%" />

</mx:Application>