What are colorfull tankmates for angelfish?

I have a 55 gallon aquarium and I want a schooling fish (tetra or barb) that is good with my 2angelfish, 2pictus catfish, rainbow shark, african brown knifefish, and a gold gourami. It sounds like alot, but my filters turn over my water like 13 times a hour. And I do 20% water changer every friday. Im wanting to add some color to it now. thanks