Aircraft livery Airlines' 1975 livery was among the first Eurowhite schemes outside Europe. The Braniff 1967 livery (see Overal Colour above) was also often dubbed "Jellybean." Jellybean liveries involve multiple alternative colourways in which entire aircraft or parts of them are decorated. A Jellybean variant involved decorating tail fins in different designs, as exemplified by Air India Express, displaying different Indian culture and heritage on its tail, Alaska Air's brand refresh livery, Frontier Airlines with the images of different animals and birds on its tail, JetBlue Airways, Mexicana, Pakistan International Airlines' "ethnic tails," and PLUNA. British Airways’ 1997 ethnic liveries were celebrated
Fin increase thrust produced by the tail of swimming mackerel". Fish use multiple fins, so it is possible that a given fin can have a hydrodynamic interaction with another fin. In particular, the fins immediately upstream of the caudal (tail) fin may be proximate fins that can directly affect the flow dynamics at the caudal fin. In 2011, researchers using volumetric imaging techniques were able to generate "the first instantaneous three-dimensional views of wake structures as they are produced by freely swimming fishes". They found that "continuous tail beats resulted in the formation of a linked chain of vortex rings" and