The sky was a midnight-blue, like warm, deep, blue water, and the moon seemed to lie on it like a water-lily, floating forward with an invisible current. – Willa Sibert Cather

It was very dark; but in the murky sky there were masses of cloud which shone with a lurid light, like monstrous heaps of copper that had been heated in a furnace, and were growing cold. – Charles Dickens, Martin Chuzzlewit, Chapter XLII

I cannot get that beautiful afternoon out of my head, above me where I lay the grass was silhouetted against the blue of the heavens, small clouds were rushing past as the wind drove them on an endless journey. – Julia Lee-Booker, letter to Pat McSwiney, 1940 July 24