Biological pigment symbiosis Trididemnum solidum, their colors are different depending on the light regime in which they live. The colonies that are exposed to full sunlight are heavily calcified, thicker, and are white. In contrast the colonies that live in shaded areas have more phycoerythrin (pigment that absorbs green) in comparison to phycocyanin (pigment that absorbs red), thinner, and are purple. The purple color in the shaded colonies are mainly due to the phycobilin pigment of the algae, meaning the variation of exposure in light changes the colors of these colonies. Aposematism is the warning coloration to signal potential predators to stay
Carotenosis Carotenosis An excess of dietary carotenoids may cause a marked orange discoloration of the outermost skin layer. This benign and reversible condition – which is most easily observed in light-skinned people and may be mistaken for jaundice – is known as carotenosis or carotenoderma or carotenodermia. Carotenemia, or carotenaemia (xanthaemia), is the presence of the orange pigment carotene in the blood from excessive intake of carrots or other vegetables containing the pigment resulting in increased serum carotenoids. Carotenoids are lipid-soluble compounds that include alpha- and beta-carotene, beta-cryptoxanthin, lycopene, lutein, and zeaxanthin. The primary serum carotenoids are beta-carotene, lycopene, and lutein.