What an instriguing idea. I must try this.Ionized air for sure. I have never seen something like that but have built earth grounded LEDs to tell me if the thunder was getting too close. Wire two LEDs together in opposing ends so that both sides had both a cathode and an anode, ground one end to earth and the other connected to an "antenna." When the strike zones are passing over, LEDs would sometimes glow. The last time where it glowed brightly was Hurricane Charley back in 2004. When I saw more than one of these things glowing in the house I started unplugging everything. Then, as predicted, within seconds every flash came with a simultaneous crash. Theres a funny feeling in the house [especially smells of something metallic burning, ozone maybe?] and I can feel my skin tingle. I have, however, never witnessed the red cloud in the house. We lost two trees and a stepdown transformer that year, the latter was a direct strike that blew out all of the house's built-in offline smoke detectors.
What you are describing is a potentially catastrophic situation, as anything with inductive properties all build up a charge, wires in conduits will heat up, breakers can open but the house circuit will still be charged... purple aura could have been ionized nitrogen... red, I'm lost on red.