[en] Humans kept ornamental fish in their homes from ancient times. During time, the ornamental fish industry became a profitable enterprise. Color, size and shape are important traits when we describe a fish as a phenotypically uniform line, strain or breed; a standardized color, shape and size describe better a fish population and thus it is promoted better on the market. Several varieties of fish are being artificially colored to improve marketability. Painted, dyed or tattooed fish are terms for a new variety of pet fish whose scales have been transformed from monochrome silver into vivid pigmentations using artificial colors or lasers. These practices produce many health problems for fish. We should not to put money above the life and welfare of any living thing. Education of the customers is a very important thing, because artificially colored fish continue to exist because of demand.