The heritage site of Brasília includes interesting buildings in apparent concrete that have successively been through reforms in the cladding and covering of their façades. The most frequent kind ofrenovation, used as often in residential architectures as in the official architectures of the city, is the fullpainting of the structures in different shades of gray. Usually, it is the social displeasure at the marks of aging on the material that motivates the choice of such a strategy, but a different situation occurs atthe University of Brasília: structures in apparent concrete are being painted gray in order to cover artistic manifestations or political graffiti made by campus' own users. The present article investigates such occurrences and researches what are the relevant cultural values taken into such choices.