Some soft corals might be okay, especially near the top of the tank. They won't grow rapidly, but the colors can be fine. I wouldn't try anything expensive at first, but some zoanthids or Xenia might do well enough. Some phytoplankton, like DT's, would help feed them.
When the tank has been stable for a while, you could look into Tubastrea or similar corals that don't have photosynthetic symbionts. They must be hand fed, but are very pretty.