Comment

In filming this intimate, tense scene, Kubrick took the radical choice of reducing his colour palate to two principal colours, suggestive of having woken from a nightmare, the cold blue of the bedroom scene where the characters are manoeuvred, and the warm yellow of room adjoined. The psychological confirmation between the husband and wife doesn’t quite happen in the real world, but in a cold, menacing parallel world, between the nightmare in the bed and the reassuring reality of the other room. The blanket blue colouring of the shots allows the dialogue to suggest a half real, half imagined event that happened in the past that threatens their relationship.

According to cinematic colour conventions the blue we see suggests a night time scene with a street light projecting through the window in to the room from the street outside. It is purely and simply a convention, created by the treatment of the film itself, for in reality light spilling from outside in to a room at night never has this specific blue hue.