Stephen Colbert's love of J.R.R. Tolkien isn't exactly a secret. I mean, he often points to his fandom as his chief geek credential and has actively debated his guests on LoTR trivia in the middle of interviews:
So I'm sure he was okay with cosplaying for Entertainment Weekly and writing a wrap-up article about the release of last Hobbit movie (and the subsequent end of the Peter Jackson Tokien-verse).
He seems fine with it.