There might be a couple hundred of these color sacks per square millimeter of the octopus' skin, and depending on the species, they can come in as many as five different colors.

章鱼每平方毫米的皮肤上可能有几百个这样的色袋，根据章鱼品种的不同，色袋可以有多达五种不同的颜色。