Maybe something dark, like a black back to contrast the green better?
What kind of betta is that?
Just finished painting a piece of wood for the background, while I like the idea of black or brown, I'm first trying a light blue, since I have the paint left over from painting my bedroom.
I don't know what kind of betta it is, my wife bought it a couple of years ago and I just asked her and she say's, "it's a blue one." I guess the tag just said male betta.