Sorry Karen, I meant to post this the first time I saw your message, but didn't get around to it!
I'm assuming you're after info about Grigorovich's production of Spartacus (premiered Moscow, April 9, 1968) which is the best known one. There have been various versions performed over the years, including one choreographed by Laszlo Seregi which is in the Australian Ballet's repertoire (also to music by Khachaturian).
Most synopsis books and dictionaries on ballet should have some notes on Spartacus, particularly if they were printed during the 1980s. However, as luck would have it, I picked up a book on Grigorovich's Spartacus just recently! It's full of colour photos of the ballet and although the book isn't very big (it's mainly written as a simple guide to the ballet) it does have some good historical notes at the front. I don't know if you'll have access to a copy so I've typed out the most relevant passages from it for you here. Hope it helps and good luck with the assignment!
From: Vanslow, V. V. and Grigorovich, Y. (1990) The Authorised Bolshoi Ballet Book of Spartacus, translated by T. Coey, Maidenhead, Berkshire: TFH Publications, Inc. pp.30-31.
"The decorative design of the production was done by the artist Simon Virsaladze who proceeded from the imaginative conception of the ballet. Like the choreographer, he rejected ethnographic and stylization. He created a generalised image of Ancient Rome. The decor contains no luxury or grandeur, creating instead dimension which intensifies the emotional atmosphere of the action.
Two arches of ancient gray stone, roughly hewn and laid, lead into the world of the ballet, as in every scene of the performance, as if by magic, they fuse into one whole with the stage set. A large sheet of canvas hangs loosely above the stage. Descending at intervals between various scenes, it forms an inner curtain serving as the background for the monologues performed by the four main characters of the ballet.
The artistic decision tends towards being multi-chrome and graphic. The choice of colours is based on the achromatic shades (black, gray, white) on which two chromatics (yellow and red) are laid. They create associations with the golden shimmer of a world of despotism and the blood-red flashes of popular uprising.
The costumes blend the same as the decor. Hence they seem to give the stage set mobility and dynamism subordinated to the rhythm of the music. At the same time the costumes also supplement the stage set by adding new shades that enrich the colour scheme.
Virsaladze subtly resolves the problem of reflecting the character of the era on the one hand, and meeting the requirements of the genre of the ballet, on the other hand. The clothing, jewelry and props, just as does the set, localise for us the time and place of the action. Yet the costumes are suited for dancing, and their material and colour structure are in keeping with the expressive movement of the performer's body.
The costumes contribute to the general spirit of the performance by creating significant images and conveying the main theme of the ballet, thus playing a meaningful role in the whole production. For that reason, for instance, Virsaladze dresses the Roman patricians for the feast scene at Crassus's palace (Act II, Scene 3) in costumes that are not so much historically authentic as they are suitable for dance and lavishly decked with gold and silver. The artist considers it much more important to convey the blinding glitter and pomposity of a mighty despotic state, rather than show exactly how the courtesans and patricians of ancient times dressed."