Red does not disappear instead the red color will "wash out" to a muted brown/grey. This is why fish like red snapper and such have the red color because at the depths they live at their color suits their environment. The depth at which red will begin to wash out depends largely on the clarity of the water and available light.

Every couple of seasons I keep switching between running a red hook up versus all black or bronze hooks. One idea that I thought about periodically is that the red on our lures/hooks or the red on a baitfish is going to react similarly under the same conditions so the fish might already be recognizing the color as red.