I think they look exactly as they should; the film is meant to reference the various styles of superhero movies... Silk fits in with the Marvel style of leather and pvc, and Nite Owl is Nolan's Bat.

One of the main theme of the book was a commentary on comics themselves, the characters in them, the different world portrayed, and how they'd work (or not work) together. Snyder has simply switched mediums and shortened the time span... now we have an Veidt wearing a bat-nipple suit, a Sin City looking Rorsch, etc. etc.