I think one thing that will help you a lot is adjusting the way you're casting the light in the scene. It looks like right now you've just got big high-radius lights sitting near every fixture, and you're getting the classic "big glow" on the walls next to the lanterns and a really harsh divide between the blue lighting on the side and this column of the warm lighting in the center, as well as dark spots where the radii of two lights don't quite fill in the gap.
I recommend that you add a lot of low-intensity and large-radius fill lights within the scene to more softly blend the colors together and get better brightness control surrounding each light. What you'll want to do is use small-radius and brighter lights around the light fixtures, then manually create a falloff with gradually darkening and widening lights as you get further away from the light. In theory you'll get more intense light sources and that better blend of color through the scene, as well as start to get a few more surfaces to "pop" with multiple light sources and colors on them, which is a big part of getting normal mapped detail to really become apparent and add to the scene.