I posted on this topic last time Rob brought it up and it was a good, informative topic. I use red trebles on topwaters, shallow cranks, and have some red trailers on my spinnerbaits. I think you''ll lose "the red advantage" in deeper water not because they're invisible. I just think they turn a darker, much less flahy red. I think fish share a lot common things with us as far as vision goes but I think they have a harder time seeing more subtle changes of color such as the diiference between blacks and darker reds. Thus a fish would probably smell fish blood (yes, even bass) in deeper waters faster than it would recognize what exact color it is. But I shallow water I think red stands out better and starts that wire in the fish's brain that says "Wounded prey!" :9

But really, I'll use red to stand out more when sight fishing bed fish too. And I can't deny the effectiveness of red flake. I mean, the CA 420 Beaver is probably the most consistently best color on my local lake! And the oxblood red flake Robo ,man, unstoppable at times. Could be that in weedy lake craws can take on more of a reddish color...who knows! And I've seen bass only hit the red hook on a topwater too. Whatever, as long as they work I'll use red hooks in some situations.