[Guinessnc]

I have a 55 gallon, fish only supported by a Fluval 305. I have the following:

3 Oto cats
2 Peppered Cory
5 Orange del Rio Tetras
5 Black Skirt Tetras
1 Red Wag Platy (The first set of fish I put in and 4 out of the 5 died)
4 Red Lamp Eye Tetras

I am thinking I need more color.

 

[roc-aquarium]

Add a couple of more platies. You'll quickly get more activity and color.

 

[Awesome]

I would also add a few more corys, they love to be in groups and there should be plenty of room for them to play in that size tank

 

[Stellaluna]

I absolutely agree about the corys. Also, you might consider getting a few more lamp eyes and tetras. With more members in their group they'll school better and be more active.