Conditional Color on fields from a sub-dataset in a table?

[dlage]

       Hi,

              I am trying to change the color of a fields value that is it a table. And the fields are part of a sub-dataset. I have tried the Conditional Styling Tags but when i add the style tags to the reportElement I get an error saying "Field not found: XML_ANSWERS --- net.sf.jasperreports.engine.design.JRDesignExpression@33ef232a"

                     my style tag :     <style name="failColor" fontName="SansSerif">
                                                       <conditionalStyle>
                                                                <conditionExpression><![CDATA[$F{XML_ANSWERS}.equals("fail")]]></conditionExpression>
                                                                <style mode="Opaque" backcolor="#FF0000"/>
                                                       </conditionalStyle>
                                               </style>