Gotham's costumer designer John Glaser gave us a behind-the-scenes peak at some of his signature outfits.

“This is Penguin’s closet, and you’ll remember certain things. His suits go from dark, but as he became the mayor, they became more purple, like this. He lost his flamboyance of wearing monkey fur and multicolored coats. He became a little more mayoral…This is Nygma’s closet and before Nygma started to transform into The Riddler, his suits were green, but they were just dark shades of green, a little more realistic. As he started turning into The Riddler, we started here, we went to here, we went to here, went to that green and now he’s here,” Glaser said. “Tabitha is just a popery of many things. She too started out with lots of sparkles, lots of studs. But now she too has fallen into a classic look which is up front.”

And there’s a specific evolution to these fashions.

“If you look at comic books and how they’re painted, we also try to paint all the clothes so that they go from light to dark. You don’t see it on everything, but as much as we can paint…even light to dark on the Arkham uniforms…And when we choose fabrics, we try to choose things that go from light to dark, so it kind-of mirrors the comic book look.”

See how they get in style for the season three finale of Gotham tonight on Fox!