Painting the railing and newel posts is not going to make them any less ornate. If there is anyway you can find it in your budget, you need to tear it all out and replace with something more your style. If that is not possible, then replacing the posts would go a long way to help, then paint everything else black. Have you tried removing the medallions? Also, I would consider removing the shorter railing all together, if it is not against code.