Yes, it certainly looks as if the curtains might be neutral gray. But there are all sorts of random color shifts/artifacts in the photo that make me think of aging film or print. I figure the best you can do is try to get the skin tones and hair looking about right.
I suspect old film is the main issue with uneven color shifts, otherwise the jacket would have more consistent color. I'd have to dig up the slide but I think it was a film from Montgomery Ward, which means the cheapest they could find. The lighting is from one or two tungsten photo lamps; my father also used an 8mm movie camera and had a set of photoflood lights (as he called them) and he used those sometimes for still photos.