Fan Casting Red Live Lobster in Sort by Tropes

While lobsters may be red when cooked, the natural colors of most lobsters are usually a brown, olive-green or gray (and occasionally blue) when alive and in the wild, which helps conceal them on the ocean floor from predators. They get their shell color from a class of red and yellow pigments called astaxanthin. However, most people don't know this. Lobsters only ever come in one variety in fiction (the Maine lobster), and even worse, especially in animation, they tend to be colored bright red. The reason many people think Maine lobster is naturally red is because, to put it in non-scientific words, they turn red when cooked. To elaborate, when lobsters are cooked, the proteins that astaxanthin bind to are denatured, changing the shell colors to a red pigment.