It's one of them. I built the all-red-light seizuredome a few years ago. The original light stopped working on the second run, so we started using Sage's light and added the fog machine. I don't have a fog machine or Sage's light, so if I was running it, it would be with no fog machine and probably all red light.

For those who were not at Firefly, it's a geodesic dome with a reflective interior surface and a variable-rate strobe in it. The strobe is adjustable over a frequency range that can induce hallucinations. So far, it hasn't actually caused a seizure, but one person did get an aura, and another person got ill. It would doubtless drop a photosensitive epileptic in their tracks.