Hi Art and all,
 
The question is not really whether color can be perceived at depths in the
ocean.  The fact is, there is nothing there to be perceived.  Color in its
essence consists of specified wavelengths of electromagnetic radiation, in the
waveband we call visible light.  In the absence of light, there is no color.
Color, as we refer to it in an object or a substance means the ability of the
object to reflect those specified wavelengths of light; and color perception
means the ability to visually (or otherwise) detect those reflected
wavelengths.  At more than a few meters depth in ocean water, there is no way
that anyone or anything can detect red light by any means, because there
simply is no red light present - the red wavelengths are all absorbed in the
first few meters of water.  Therefore nothing can look red to the eye or to a
camera.  A red wetsuit looks gray.  That is why photography in those depths
requires artificial lighting.  The white light of an electric lamp includes
red wavelengths, which can be selectively reflected by objects having the
inate ability to do so.  However, in the absence of white light or some other
source of red radiation, such objects are not in fact red - they can only be
said to be potentially red.  They possess the ability to appear red if and
when red light becomes available.
 
Paul M.