Koi fish tattoos are a type of body art that have been popular since the beginning of time. The koi fish is an ancient Asian symbol of luck and prosperity, and it is also associated with strength and courage. Koi fish tattoos are often brightly colored and usually feature two or more koi swimming in a pond or lake. The colors of the koi fish can vary, but the most popular colors are red, orange, yellow, and blue. The design of koi fish tattoos can be simple or elaborate, depending on the wearer's preference.