Look at the flickering faces in the original Tron's composite screens, grainy high contrast black and white just tinted a little. That's a very deliberate choice, and given the prominence of Metropolis chances aren't small that the inspiration wasn't just any silent era look (granted, they all looked like that), but straight from Fritz Lang.
It caused me to wonder if Tron was a world inside a computer ... or our own future (and, sure, why not both).