The Forgotten Environment: Shade

Shade is not the absence of light. It is light filtered, scattered, and reflected — often from the sky alone, with the direct sun blocked. The spectrum shifts noticeably cooler under open shade, since the dome of blue sky becomes the dominant source.

Under a forest canopy, the spectrum shifts the other way: green wavelengths transmit and reflect off leaves while red and blue are absorbed. The result is an environment most people experience as restorative — possibly because the visual system is doing less work, and possibly because something deeper recognizes the shape of a forest as safe.