What does rainbow fish mean?

Here's a list of possible definitions for the term rainbow fish:

guppy, rainbow fish, Lebistes reticulatus(noun)
small freshwater fish of South America and the West Indies; often kept in aquariums

rainbow fish
The Rainbow Fish is a children's picture book drawn and written by Swiss author and illustrator, Marcus Pfister, and translated into English by J. Alison James. The book is best known for the distinctive shiny foil scales of the Rainbow Fish. Decode Entertainment turned the story into an animated television series of the same name, which aired on the HBO Family television channel in the United States and Teletoon in Canada from 1999 until 2000.

Rainbow Fish
The Rainbow Fish is an award-winning children's book drawn and written by Marcus Pfister, and translated into English by J. Alison James. The book is best known for its morals about the value of being an individual and for the distinctive shiny foil scales of Rainbow Fish. DHX Media turned the story into a 26-episode animated television series of the same name, which has aired on the HBO Family television channel in the United States since 1999.

Chaldean Numerology
The numerical value of rainbow fish in Chaldean Numerology is: 5
Pythagorean Numerology
The numerical value of rainbow fish in Pythagorean Numerology is: 7