Export more data from a table p: dataExporter

I have a simple table: (Example based on the official website)

<p:dataTable id="carId" var="car" value="#{dtBasicView.cars}">
    <p:column headerText="Id">
        <h:outputText value="#{car.id}" />
    </p:column>

    <p:column headerText="Year">
        <h:outputText value="#{car.year}" />
    </p:column>

    <p:column headerText="Brand">
        <h:outputText value="#{car.brand}" />
    </p:column>
</p:dataTable>

With the element

<p:dataExporter type="xls" target="carId" fileName="NombreExcel" encoding="ISO-8859-1"/>

I created an excel with the fields that the table contains, but how could I get another field that is not in the table?

That is, the Cars class has the fields: id, year, rand y color . The color attribute is not shown in the table, can it be added to the export?

PS: As a possible solution, I have seen that I can add the column to the table and hide it with: style="display: none" but I need to add about 30 more fields, I look for another more efficient solution.

I have already seen to modify the export the method is used: postProcessor

<p:dataExporter type="xls" target="carId" fileName="NombreExcel" encoding="ISO-8859-1" postProcessor="#{dtBasicView.postProcessXLS}"/>

public void postProcessXLS(Object document) {

That Object can be an Excel, PDF.