I have heard that you always want to match your shoes with the hem of your dress. You might want to add another turquoise item such as earrings or necklace to match the sash.
Since it is highly unlikely that you could exactly match the shade of chocolate in a shoe, then you must turn to black; patent leather would be nice but a matte shade will work. Just remember, you cannot wear brown unless the match is absolutely identical. That would be the worst (except for turquoise, which would be ghastly).
The new rage in shoes this year is to go with something bright, therefore I would try and find a tourquoise shoe, or at least one with tourquoise accents.
A brown shoe would go nicely to pick up the chocolate color of the dress. Or if that is not an option, you can go with a silver shoe which is a nice neutral shade.
Try to find a pair of turquoise shoes. If you can't find that, pick a color that would look good with the outfit for accessories (earrings, necklace, bracelet ect.)