Conditional Coloring of Datatable in PF or var vs binding tags in a datatable

I have a datatable and a collector. Each row in the datatable has a button and this button adds the corresponding row to the collector. I want to add conditional coloring to this datatable. Condition is whether the selected rows are in the collector or not.

<p:dataTable rowStyleClass="#{backingBean.selectedMemberList.contains(aMember) ? 'passive' : 'active'}" style="width: 100%;" id="dTable" var="aMember" value="#{backingBean.memberList}">
    <p:column>
    ...
   </p:column>
 
   <p:column>
       <p:commandButton id="btn_add" value="Add" update=":mf:op" process=":mf:op_uk">
           <p:collector value="#{aMember}" addTo="#{backingBean.selectedMemberList}" />
        </p:commandButton>
   </p:column>  
 

backing bean:

List<Member> selectedMemberList;
 List<Member> memberList;
 
 //getter and setter methods
 

Above code does passive style class but does not add active style. I thought it is maybe because I can not pass var (which is request scoped) to backing bean.. So I tried binding the value to a backing bean value:

<p:dataTable binding="#{backingBean.anotherMember}" rowStyleClass="#{backingBean.selectedMemberList.contains(aMember) ? 'passive' : 'active'}" style="width: 100%;" id="dTable" var="aMember" value="#{backingBean.memberList}">
 

backingBean:

private Member anotherMember;
 //getter and setter methods
 

but it did not work either. Does anyone have any recommendation about this issue?

PrimeFaces ver 2.2.1

EDIT:
css contains these fields:

.active{    
     background-image: none !important;   
 }
 
 .passive{
     background-color:gainsboro !important;
     background-image: none !important;
 }
 

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