Everyone seeing less colour in poor light. I'd be inclined to get that look in postwork -- make a mask based on brightness, and then take the colour out of the darker areas of the scene. What I've seen, smoke from the fire, once chimneys were invented, is a pretty localised sort of effect. Candle smoke is more significant generally. You do get traces around the hearth. Maybe use one of the gradient shaders in P5. I do recall the family using paraffin lamps during the miners' strike of the Seventies, but I've no clear recollection of what a lit lamp looked like.