Which do you think looks nicer and shows off mbunas colors better, such as yellow labs, red zebras, cobalt blues, socolofi...
1.) Blue background, black sand
2.) Blue background, light sand
3,) Black background, black sand
4.) Black background, light sand
I vote for number four. A black background gives the colors something to stand out against. I think a light color substrate works better because the light from the hood will reflect off of it better and light up the fish a bit from below as well.
That's what I did when I was trying to decide. I looked at the "Your tanks" section. You'll see every possible combination there lol. I went with black background and light colored gravel (partly because light colored was what I had lol). Some time I'd like to try a smaller tank with black background and black sand too.
I definitely prefer a black background (my fry tank has a blue background and I don't like it as much) because the fish really stand out. Additionally, the algae growing on the back of the tank looks really cool/natural against the black and not so nice against the blue.
I think black sand with a black backround looks very dark... I like my multi-colored sand because it's not so light that it looks "dirty." (White sand doesn't stay white for long!)