[JustOneMore20]

Can you measure the length, width, and height? Thats the best way to tell what size tank you have.

Black Skirts aren't colorful, but if you like them, that would be fine along with 1 or 2 Bolivian Rams. You may want something else to occupy the bottom, thats why I suggest cories. 6 won't be alot. If the tank is truly a 20g long, its 30" long and that is alot of floorspace for bottom feeders.

If you can fine Dwarf Cories (Corydoras pygmaeus, C. hastatus, or C. habrosus), you could have even more.....I'd say 8-10, since they all stay around an inch. They aren't colorful either though.

If you want color, go with the Bolivians and then a school of 8 colorful tetras. Or you could possibly have 2 schools of 6 if you chose small fish.