Rainbow Fish is a 2000 British animated children's television series adapted from the book of the same name by Marcus Pfister. Unlike the book, the television adaptation didn't follow the plot; instead, it takes the character and the setting and creates a new story with them, with some characters being added and others embellishing for the purposes of the series, in which the place where the fish live is called "Neptune Bay" (after Neptune, the god of the sea), with the fish mostly attending "The School of Fish". It also features a shipwreck called "Shipwreck Park" (which resembles the wreck of the RMS Titanic). The series was produced by Decode Entertainment and EM.TV in association with Sony Wonder.
The Italian dub's title is Arcobaleno. This Dub Used To Air On Rai 3, and the cast, as well as episode titles are on Italian Wikipedia. Some episodes are on YouTube.
References[]
https://dubdb.fandom.com/wiki/Rainbow_Fish_(TV_Series)?so=search