[AlphaAndOmega0]

To me, it seemed to be a visual equivalent of that auditory trick where a note seems to descend or ascend in pitch indefinitely. The outer aura of color seemed to be shrinking constantly.

[drcongo]

The Shepard Tone - https://en.wikipedia.org/wiki/Shepard_tone - brilliantly used by Hans Zimmer in the Dunkirk score.