The blue top is the only Hula Shirt that was supposed to be available, but the outfit was accidentally released with a yellow top instead. Those players who had purchased the outfit in 2009 when it had the yellow top were allowed to keep their yellow shirt, as well as being given the blue shirt.
This article refers to items, events, personae and activities only available in-game during the Seaside Summer Splash celebration, which ran from July 3 to July 15, 2009. (Introduced in 2009)