Peter Ackroyd

such an atmosphere of mist and moisture, blue and yellow may seem brighter but red will be more subdued. Natural light changes the visual field. In the interiors of stores and houses, lights are cool and shadows warm; in the outdoors of daylight, the lights are warm and the shadows cool. On south fronts subdued
colors will seem to be brighter, and on north fronts bright colors are dulled.

Turner, like any true Londoner, loved fire. It was part of his inheritance, in which flame expressed a truth about the fabric of the world.