2001 was shot in the format officially known as Super Panavision 70mm/Cinerama. With the original Cinerama, developed in the early Fifties, takes were filmed by three cameras simultaneously, so as to widen the field of view as much as possible and to produce an image as close as possible to that of the human eye. Similarly, screenings required three 35mm projectors to operate from the same booth projecting their respective portions of the image onto a large, curved three panel screen. In optical terms, the screen reached 146 degrees in width and 55 degrees in height.
In an effort to reduce costs while still obtaining equally spectacular results, in the mid-Sixties the three-camera shooting system was replace by Ultra Panavision, which utilised just one camera loaded with 65mm film (capable, therefore, of very wide angle shots and a ratio similar to that of the original Cinerama, even if no longer able to reach a 146 degree field of view). […]
Then, towards the end of the Sixties, Ultra Panavision was in turn replaced by Super Panavision 70, a system that continued to use the ‘Cinerama’ trademark, even though it was not as wide as its predecessors. Also, under this system, the frame to be projected measured 70mm and was obtained from a 65mm negative. It is the format of 2001, exploited to its full potential only in several major cities: in most other cases the film was screened without the use of a curved screen and, beginning in the autumn of 1968, in the ‘normal’ 35mm format. During the shoot Kubrick used more than one type of camera, essentially: Mitchell for 65mm and Panavision.In the view of some critics, Super Panavision 70 is Cinerama in name alone; despite this, the vision of 2001 on the big screen remains a breathtaking experience, one repeated again in more recent times. In 2001, to honour its titular year, some European film theatres re-screened the film in its full 70mm splendour.

Giuseppe Lippi, 2001: Odissea nello spazio. Dizionario ragionato, Le Mani, Recco 2008

Enclosed spaces in Kubrick give off their own light, enclosing characters in a sort of aquarium. The toilets and bathrooms in The Shining, the bar in A Clockwork Orange, HAL’s brain, the Hilton Hotel, the bedroom and bathroom of 2001 all have walls that appear to radiate light.
White is found almost everywhere in Kubrick’s films. […]. In 2001, the white sets literally radiate; the audience bathes in light from the screen.
Red is the second most important colour. For reasons more symbolic than scientific, 2001 encourages us to see some settings as representing the interior of the human body. This effect is particularly noticeable for the underground area of the moon base, and in the airlock where Dave manages to get back into the Discovery.
In contrast to the many brightly lit images, some shots show the total darkness outside in a terrifying manner. In the scene where Bowman recovers Poole’s body, the images and soundtrack bring out the immensity of the void where the action takes place: the pod, piloted by Bowman, and the floating spacesuit containing Poole’s body are depicted as tiny dots of matter and light in an ocean of silence and blackness. It is intentional that the lights and the stars, in the sky of 2001, are dull. The symphony of lights during the finale becomes that much more impressive.

Michel Chion, Un’odissea del cinema. Il ‘2001’ di Kubrick, Lindau, Torino 2000