There is a FAQ for this forum that should help. I have never seen a non black liner either. I think paint would make a mess. Fortunately, algae and other crud will naturally color your walls after a while.

Will this just be above- ground?
If you're okay with the color, I would give it a try, as is.
You're in a warm area, so its not like you need to attract warmth to the black.

You could get a very small pump and either just have it spout water in the middle, or you could buy a spitter of some type and put it to the side. (Although if this is to be above ground, that wouldn't work). What I did with smaller water features is just put the pump at the bottom and let the rigid tube come just above the water's surface, and let it bubble like that. They also have floating things that bubble too, that you connect a tube from the pump to. Another thing you could do is put a black plastic milk crate in the middle, and put some spitter on top of that. I've seen things like small ceramic/resin vases that you could put on a crate and they would over-flow in the middle of the water feature.
Lots of possibilities!