This article describes a method of treating fire-damaged 20th-century paintings whose surface has turned brown. Solvents that are employed for older, well-dried oil paintings cannot be used for paintings of more recent vintage, because they attack the paint surface. According to Christopher Tahk, the brown discoloration of the surface is caused in most cases by complex physical and chemical changes in the binding medium, which is less heat-resistant than most pigments. In a series of experiments with exposure to radiation from eight fluorescent tubes, Philips TL 47/20W, which have the least output of ultraviolet radiation, the author observed that the light pigments became noticeably lighter and the dark ones did not change perceivably. After exposure for 1200 hours equivalent to a brightness discharge of 3600000 l x h, the paintings could be cleaned with diluted Vulpex soap, which had had no effect prior to the exposure to fluorescent rays. The results of Tahk show that an additional exposure has no significant bleaching effect. -- AATA