I think red hooks have their uses. Sure BassPro and others have hyped out "the red theory". But I use them at times in shallow water if I want to see my bait, like when I'm sight fishing with a drop shot rig. When I drop that rig on the bed, I can see that hook flash as I shake it from over 20 feet away. It often works to get at least some bed fish to hit because it's just a bit more visible to both them and me. But like you said, red disappears in deep water. But it is hype to that red will turn black at shallow depths too. It takes about 30 feet of water column for red to begin changing. So, I guess there is 2 sides to the whole red hook thing?