Anemone theory...artificial colouring...

[Aquattro]

I have no idea what it would look like, but the leathers and anemones I've seen were very solid bright pink or yellow. I understand they soak them, as this critters fill their tissue with water and recycle it. This "inhalation" of the water gives them color and I suppose some goes deeper into the tissue. They do eventually go back to the normal color if they don't die first.