Time required to evolve advanced chromatophores in octopuses and squid?
Here is a print screen from oneZoom.org.



Coleoida include decapods and octopods, both of which have chromatphores, so their MRCA (which lived 330 millions years ago) probably did as well. Coleoida is a sister group to the nautiloids. They branched +400 millions years ago. Together they form the group of cephalopods. As nautiloids do not have chromatophores, the evolution of chromatophores probably occurred in between these two nodes (between MRCA of cephalopods and MRCA of coleoida). In other words, it occurred at some point during a period of about +70 millions years.