That would be amazing!
I've read somewhere (can't recall where tho') that many cephs have been found to contain colour pigmants in the retinal cells of the eye, so while they may not see the range of colours that a critter with dedicated colour cells can, they may very well be able to see some colour.
I'd love to know where you read that! I'm trying to collect references for a little article about ceph vision and color (since it seems to come up here every month or so) and I haven't found any reference that describes any ceph other than the firefly having more than one visual pigment, although there is anecdotal evidence that at least one GPO seemed to react to red clothing, and apparently Ossie seems to be able to see a red LED flashlight, although her keepers seemed to have better luck not scaring her using that than white light...
Hanlon & Messenger's Cephalopod Behavior
has most of page 19 devoted to this question, and, in referring to that box from the text on p. 20-21 they say "All these results[of behavioral experiments], together with the morphological, biochemical, and physiological data... suggest strongly that O. Vulgaris
is colour blind. To what extent other cephalopods are colour blind is not known, although there is some experimental evidence that O. apollyon
(Roffe, 1975) and also Todarodes pacificus
(Flores, Igarashi & Mikami, 1978; Flores, 1983) may be colour-blind. Apart from the firefly squid, the evidence is that most cephalopods are colour blind."
They go on to demostrate that most ceph color matching of the background comes from reflecting the light without changing its color, rather than the animal perceiving and actively matching the color using chromatophores, in Box 5.1 on the color plate after page 70.
They also say that "Until 1973 there were conflicting reports about whether cephalopods had colour vision. All these accounts were flawed in experimental design (or lack of it)..." Of course, it sounds like Messenger has pretty strong and possibly controversial opinions on the subject. Nixon & Young seem to lean towards agreeing with Messenger, at least in the case of O. Vulgaris
and S. Officionalis
, but I'd still be very interested in reading any paper that does describe color vision in cephs other than the firefly squid (Watasenia scintillans)
This paper also describes the firefly squid's visual pigments:
Just free associating with bioluminesence and NZ, have any of you Kiwis or your visitors gone to the underground river that has glow worm caves? A couple of friends have told me that if I'm ever in NZ, I should be sure not to miss them...