London in a Purple Hue

Pastel drawing by Joseph Pennell (1857-1926). View of London in dark blue and purple light under a sky richly lighted with the late evening sunset glow. Colors, blue, green, purple, rose, orange, white, black, gray, and violet on brown paper.
source: http://www.loc.gov/pictures/collection/drwgma/item/2007666812/