And was totally stricken by the flowing white blotches and their colorful bloom. I've been trying to decipher how the video was made, and so far I have, uh: well, there are at least two layers, and there's probably some sort of blending mode being used between the layers.
If anyone could help me understand how those effects were achieved and how those images were created, I would be very grateful.
There are multiple layers of action. Possibly some video, others motion graphics. Some of the layers are working as alpha mattes for other layers. There are a couple adjustment layers that are working to colorize the footage. Something like glow is applied over it all to make the bloom.
Since it's on youtube, why don't you just email the guy and ask him?