Octopuses can change the color of their skin in an instant and, like other coleoid cephalopods, can use color as visual communication. However, cephalopods are widely accepted as color blind as they do not have multiple kinds of photoreceptors.
Controversial research suggests that octopuses and other coleoid cephalopods might use chromatic aberration to essentially measure the wavelengths of different colors in order to discriminate between them.
for more info check out Stubbs and Stubbs 2016 paper, Spectral discrimination in color blind animals
