The colour schemes we are going for in the opening sex scene (Stan and Sasha) is deep reds and big shadows. Without wanting go into too much detail on how we plan to achieve this (Stefan is a much better person to explain this), I just wanted to upload a couple of clips that lean in the direction of the look we are going for.
As a side note, the sex scene with Lily at the end will follow the colour and look of the rest of the film but as the intensity build up and we cross-cut between that and the Sasha scene, the red will creep in, blurring the line between what is happening now and what has already happened.
The following scenes are from The American for the colour and from Lust, Caution to give an idea of the the lighting/shadows etc.
NB: Content more explicit than I am intending to go, but watch for cinematic techniques/devices