In the Upper Basilica , reopened in 2000 after intense round-the-clock restoration , Cimabue 's works in the apse and left transept have turned black , looking like photo negatives because of the oxidized white lead in his paints , yet you can still feel the intensity of the crowd 's anguish in his Crucifixion , blessedly untouched by the earthquake 's damaging force .
The white lead in the paint of Cimabue 's work has oxidized and turned black .