A Black and White Tank!

Without realizing it, I now have a black and white fish tank! In my
50-gallon bowfront, I now have: 6 cory cats (not sure of the variety,
but they are quite small, with black and white zebra stripes), 2 tiny
angels (blank and white/silver striped) - they will get bigger, and 3
female dwarf gouramis (all silver). The only source of color are my 2
MALE flame gouramis, who are a nice orange/red with a blue fin. How on
earth did I wind up with such a monochromatic tank?

Any suggestions on what else can I add (eventually - not right now,
since I am adding gradually) that isn't black or white/silver??? I
have SOFT water, with 0-0-10 parameters for ammonia/nitrite/nitrate.
Could I add some discus? I know that they can be quite colorful. I'd
like something with some size, since everything else seems small.

Thanks,

- Lisa