The term 'Colorful Aquarium Swimmer' can be broken down into two crossword solutions: Angelfish (9 letters) and Tetra (5 letters). Angelfish are a type of freshwater fish that come in a variety of colors, including yellow, orange, silver, and black. They have long, flowing fins and are popular in home aquariums. Tetras are also a type of freshwater fish that come in a variety of colors, including red, blue, and green. They are small, schooling fish that are also popular in home aquariums. Both Angelfish and Tetras are colorful, active swimmers that make great additions to any home aquarium.