Yesterday's 8.1 Magnitude Earthquake off the coast of Mexico was massive, and has caused significant damage and loss of life.
The quake was over 400 miles away from Mexico city, which escaped the worst of the damage, but still experienced deep swaying that caused lights and signs to swing around. One of the more dramatic results (in Mexico city) was numerous sparks, flashes, and bright explosions from power lines being damaged by the swaying, like in this video.
The sky above was covered with a low layer of cloud, so the various flashed and explosions reflected off this, like in this video:
When you can't see the transformer explosion or arcing, the flashes looked like strange lights in the clouds, almost like lightning.
In this footage you can see a combination of the cloud lights with a matching flash on the ground, and more distant lights where the explosion is not visible.
Note that these are different colors
The light color varies because electrical explosions are colored by the environment of where the flash is. Both in terms of the chemistry affecting the plasma of the flash, and reflections from the immediate environment.
The position in the sky also varies. The cloud layer is pretty flat, like a ceiling, so the more distance flashes look lower (where the illuminate the clouds), the closer flashers look higher. The very close flashes/explosions illuminate an area of cloud off the top of the image.
The transformer explosion I used for the top illustration is from this video:
You might not think it's bright enough to illuminate the clouds, but that's because the frame I used is not of the actual explosion, which just looks like a white screen because it's so bright. Here's ten sequential frames from before, during, and after the explosion.