On Colors of Dead Leaves

Yellow, and black, and pale, and hectic red (Shelley, Ode to the West Wind):

O WILD West Wind, thou breath of Autumn's being;
Thou from whose unseen presence the leaves dead
Are driven, like ghosts from an enchanter fleeing,
Yellow, and black, and pale, and hectic red,
Pestilence-stricken multitudes! O thou
Who chariotest to their dark wintry bed