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
Through colour render Through colour render Through colour render is a sand/cement/lime based render that is made from White Portland cement (WOPC) and added pigment to produce a coloured effect that is throughout the body of the material. The pigment is preblended into the product as part of the manufacturing process to produce a prebagged product. Another name for these type of materials is monocouche renders. Various mix designs can be produced in renders according to the published Code of Practice for External Renderings, BS5262 1991. The through colour render market within Europe produces a class 3 mix design as per the Code