How to Tell When an Octopus is Dreaming

Freaky deaky...

Now if we could just make a coat out of them...

My brother says they obviously dream in color...

Is the color changing involuntary, like breathing, or consciously controlled like speech?

it might be both...like breathing.

Breathing defaults to involuntary as in when we sleep.. Our vocal speech depends on the voluntary aspects of our breathing.

Interestingly, the octopus is color blind. The eyes only have one type of detector. So, how do they see color? One theory is that they employ chromatic aberration. As the eye focuses, color is detected by what detail is in focus.

https://carnegiemnh.org/octopus-mystery-how-do-they-see-color/

I haven't spent much time observing the octopus, but I have seen images where it is not in camo, so it seems it can't be "automatic", it has to be voluntary or as truthisnotacompromise says, could be both, and involuntary when sleeping. The notion that the color change is a response to dreams sort of puts it back in the 'voluntary' camp though.

Involuntary camo while sleeping I would expect to produce a true camo to its environment.

The fact they can't see color is amazing.... their camo sense is something we can only imagine.