In our night vision, all colors fade to blue-gray-charcoal except for white, which lights up the darkness.
When we can concentrate in meditation, all sensory input fades to the background, while our object of meditation (breath, hearing, or feeling) draws our attention completely. If the mind doesn't exactly fade to stillness, it quiets to wispy whisperings, giving rise to a deep sense of calm.
In the moonlit garden, my senses are limited to the sight of white and the fragrance of phlox and Nicotiana.
Oh, smell the calm.
Photo from gomestic.com