reading the orcs as "black" is disengenuous

since people are not literally BLACK, but varying shades of brown, the darkness of the orc skin is not a melanin darkness

you've got to consider the literary traditions and dialogues that LOTR grew out of
Victorian fantasy, Victorian sci-fi, Victorian fabulists... evolution and devolution, class struggle and industrialization
for instance in HG Wells "The Time Machine", and G Macdonald's "The Princess and the Goblin" they tell the story of people been kept underground so long that their skin pales into a sort of dull grey. And this is grounded in the theory of how evolution will effect human appearance in the future, and the increasing ACTUAL banishment of workers to factories from before dawn to after nightfall, or worse to coal mines for 16 hours a day or whatever. So, ironically, the orcs have more in common with the white people of Britain than with the dark skinned people of Africa. Indeed in the books and the films they live in(side) the mountains or mines. It is true that the only non-pale humans in LOTR are the ones who fight for Sauron... but their culture is not included in the literature, and they are presented as mercenaries. They hail from a land further south (therefore darker skin in the normal sense) but we have no idea what those lands are like.

I don't know much about King Kong... but evolution was a world shaking theory and for decades writers were preoccupied with the notion that we are descended from apes (monkeys did not enjoy the same lovable reputation in those days... most people would never have seen one), and the idea that there is something uncontrollable and monsterous in human nature (see Mister Hyde's 'ape-like fury')

so anyway to overwrite these dialogues with this postmodern discourse on racism seems a bit nuts to me (in cases like that sensationalist article in The Guardian)