Chromatic Shadows

Shadows aren't the absence of light; they're regions lit by different sources.

The painting below shows a warrior standing on a ledge. He is lit by a slanting bar of light that shines from below.

Note that the cast shadow from his arm is red on the bottom and blue above.

The colored shadows suggest that the scene is lit by two adjacent spotlights, a red one below and a blue one above. This is typical of theater lighting, where two o…