if (parseFloat(data.col1.length) != 9){
        (setStyle("color", (parseFloat(data.col1.length) != 9) ? NEGATIVE_COLOR : POSITIVE_COLOR))
    }
	if (parseFloat(data.col2.length) > 15){
	(setStyle("color", (parseFloat(data.col2.length) > 15) ? NEGATIVE_COLOR : POSITIVE_COLOR))
    }
		//:setStyle("color", (parseFloat(data.col2.length) > 15) ? NEGATIVE_COLOR : POSITIVE_COLOR);
    }
    }

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2007/09/25/creating-a-custom-combobox-item-renderer-in-flex/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="top"
        backgroundColor="white">
 
    <mx:Script>
        <![CDATA[
            protected function selectStateByName(stateName:String):void {
                var states:XMLList = statesXMLList.(@name == stateName);
                if (states.length() > 0) {
                    comboBox.selectedItem = states[0];
                } else {
                    comboBox.selectedIndex = -1;
                }
            }
        ]]>
    </mx:Script>
 
    <mx:XMLList id="statesXMLList">
        <state abbrev="AL" name="Alabama" />
        <state abbrev="AK" name="Alaska" />
        <state abbrev="AZ" name="Arizona" />
        <state abbrev="AR" name="Arkansas" />
        <state abbrev="CA" name="California" />
        <state abbrev="CO" name="Colorado" />
        <state abbrev="CT" name="Connecticut" />
    </mx:XMLList>
 
    <mx:ApplicationControlBar dock="true">
        <mx:Button label="Select California"
                themeColor="haloGreen"
                click="selectStateByName('California');" />
        <mx:Button label="Select Oregon"
                themeColor="red"
                click="selectStateByName('Oregon');" />
    </mx:ApplicationControlBar>
 
    <mx:ComboBox id="comboBox"
            prompt="Please select a State..."
            dataProvider="{statesXMLList}"
            rowCount="3"
            labelField="@name"
            itemRenderer="ComboBoxItemRenderer" />
 
</mx:Application>