In “The Masque of the Red Death,” the seventh room is black, with scarlet light shining through its windows. This final chamber is the most ominous of Prince Prospero’s seven rooms and is largely avoided by the revelers.
The rooms form a sequence of colors: blue, purple, green, orange, white, violet, and finally black. The black room’s red illumination creates an unsettling bloodlike effect. It also contains a large ebony clock whose hourly chimes interrupt the party, forcing the masked guests to confront time and mortality before they resume their revelry.
At midnight, a mysterious figure dressed like a victim of the Red Death passes through the rooms and reaches the black chamber. Prospero dies while confronting the figure, and the guests discover that the costume contains nothing tangible. The story ends with darkness, decay, and the Red Death possessing total dominion. Poe first published the tale in 1842.