What is the complementary and the opposite intensity of white?

Well it's absolute opposite is infact black. But as soon as white is 'dull' as you say, it is combined with some other hue, taking it into the spectrums of yellow, or blue, etc. But a true gray-white's derivitive is black. The question is, what is the black comprised of...extreme dark blue or brown or green etc. Interesting! ;)