Octopuses use camouflage when hunting and to avoid predators. To do this, they use specialised skin cells that change the appearance of the skin by adjusting its colour, opacity, or reflectivity. Chromatophores contain yellow, orange, red, brown, or black pigments; most species have three of these colours, while some have two or four. Other colour-changing cells are reflective iridophores and white leucophores. This colour-changing ability is also used to communicate with or warn other octopuses. The energy cost of the complete activation of the chromatophore system is very high equally being nearly as much as all the energy used by an octopus at rest.
ocToPuSes uSE camOuFlaGe WhEn HunTIng and tO aVoID prEdAtorS. tO do THiS, they use speciAliSed skin cells THAt cHANgE the appEaranCe OF tHE skIN by aDJusting iTs CoLoUR, opaCIty, or reFlEctIvIty. chroMAtophorEs ContAiN yelLOW, orange, rEd, brOwn, or blaCK piGmeNTs; most speciEs hAvE three of THeSe coLOurS, WHile Some Have two or fouR. OtHEr coLOuR-cHanGing ceLLS are ReFLectivE iridophOreS and white LeucophorEs. this COlouR-chAngIng aBility is also UsEd tO cOmmUNicaTe With Or wARn oTHeR OctOpUseS. the ENeRgY cosT OF the ComPLete activAtIon oF the ChromatOphoRe sYsTem Is VeRY High eQualLy bEinG neARly as Much aS all tHe eneRgy UsED By an octOPus at Rest.