yeah, I bought a background that has one side blue and the other black..
I am leaning towards the black side but I don't know until I see it with the black gravel in...
I am thinking:
black stand
black trim
black silicone
black gravel
black background LOL
with silvery fish (more barbs, redhooks etc and perhaps some south american cichlids (severums, geophagus), it might look pretty cool...