When shrimp is raw the flesh is a grayish color. As it cooks, it turns to an opaque whitish pink color. The shrimp should curl up into a loose “C” shape when properly cooked. If they have curled up into a tight “O” shape, then it is most likely overcooked. (An undercooked shrimp will still have some grayish spots on them and form more of a flexible “U” shape.)