The chromatophores in the skin of Sepioteuthis appear as colored blobs embedded in a semi-translucent surrounding dermis. They exhibit a variety of colors, shapes and sizes within and amongst species. In this image we can see varying shades of reds, yellows, and black.

The chromatophores are controlled by muscles that are in turn controlled by nerve fibers connected to the brain. The squid can relax or contract these muscles and change the size and shape of the chromatophore. A nerve fiber may have control over several chromatophores. Different colored chromatophores are therefore controlled by different nerves. By controlling the relative sizes of different colors the squid is able to change the hue and intensity of its skin.

Click the image to see the effect of this contraction and expansion of the chromatophores.