div.stub span, div.stub address, div.stub *|q, div.stub *|r { background-color: red; }
address, *|q, *|r { display: block; margin: 1em; }
div.stub *:not(p) { background-color: lime; }

 <div class="stub">
  <p>
   <span>The text in this paragraph should have a green background</span>
  </p>
  <address>This address should have a green background</address>
  <q xmlns="http://www.example.org/a">This element in another namespace should have a green background.</q>
  <r xmlns="">This element without a namespace should have a green background.</r>
  <p>This paragraph should be unstyled.</p>
 </div>