I have a 50 gallon tank I am getting ready to start up again. I want some fish that will grow to a decent size that offer some color to the tank as well. I know from the past that aggressive fish tend to be more colorful. I have a young daughter that I want "pretty" fish for her to see. Goldfish are easily out of the question. I am not overly concerned with fish outgrowing the tank as I am planning a larger tank in about a year. Any suggestions and/or advice?