I took this photograph from my apartment which shows the city lit in a violet light from lightning, which is outside of the photo's field of view. The Hilton Hotel tower's south wall shows the effect most effectively. (I did get one decent picture of a bolt of lighting but not relative to this forum for posting.)
I observed the view for an hour but did not see any sky to ground lightning strikes. All of the lighting I saw from cloud to cloud.
Lit by Lightning - 9-11-2017