Yes — I was shooting video and did an image capture. No, I was not using strobes or video lights — they wouldn’t have helped at the distance the school of hammerheads was at. And yes, I was at 140 feet, but I don’t think I was narced. The main point of saying that I was at 140 feet is that at that depth, there is very little or not red spectrum light getting through, yet the sharks I observed (and the divers, for that matter) definitely did not appear as blue as in my images, camera white balance notwithstanding.
I think many of the people who responded understood my question as I intended it: why is it that we are able to perceive colors underwater with more apparent fidelity than a camera sensor? Some interesting answers have been offered, a few of which seem complementary (no pun intended), a few of which seem at odds with each other, but lots of food for thought.