I like the black best.

I like the black and think it looks great, but I would go with a narrow black inner border than one of the prints (maybe the black with he swirl and flowers) for the outer border and then bind it in black. Or maybe applique some of the fish on the black border. Just dreaming, whatever you choose will be lovely.

I think the black makes the colors stand out more. :-)

Black, have you thought of the dark teal that is in the blocks, might be a nice accent color.

HAVE YOU TRIED A BURGANDY OR A RED???

I like the black subtle pattern you've chosen. A solid black would be too stark.

Black.

out of these two colors I prefer black

black

Black makes the square more dramatic.