@namespace html url(http://www.w3.org/1999/xhtml);
@namespace a url(http://www.example.org/a);
@namespace b url(http://www.example.org/b);
div.stub > *|* { color : red ; display : block ;
                 margin-bottom : 1em }
div.stub > *|*:not(a|*) { color : green  }
div.stub v { color : green }

<div class="stub">
<address>This address should be in green characters.</address>
<s xmlns="http://www.example.org/b">This paragraph should be in green characters.</s>
<t xmlns="">This paragraph should be in green characters.</t>
<u xmlns="http://www.example.org/a">
<v>This paragraph should be in green characters.</v>
</u>
</div>