The penetration of sunlight, for the ocean, can be described as merely illuminating the surface.
In the ocean, below a depth of 200 meters, the human eye can no longer capture sunlight at all.
At depths between 200 meters to 1000 meters, there are still some light-sensitive organisms that can use their eyes to catch the sunlight, but at this depth, no organism can perform photosynthesis anymore.
As for below 1000 meters, it is complete darkness; all known Earth creatures can no longer perceive sunlight.
And the average depth of the ocean is 3347 meters, with the deepest point at the Mariana Trench reaching up to 11034 meters.
That is a darkness where sunlight cannot penetrate at all.
"The red glow needs to be bright enough to affect the mutation of living things. Initially, it only affected the creatures within about 200 meters deep of the ocean, beyond that, it could not. It basically had no effect on the deep sea. But..."
