Postcards from the Imagination

"Discovery of the pigment emerald (Schweinfurt green) in 1800 further worsened the repute of green as the color of poison. Emerald was prepared from verdigris and copper arsenite to result in one of the deadliest poisons ever used in painting. Green was the favourite color of Napoleon and the green wallpaper in his exile home in St. Helena became his undoing. His premature death was not the work of a poisoner but was caused by the noxious fumes emanating from the bright green wallpaper."  from Pigments through the Ages.