The Deletion of Docker.io/Bitnami

Yes. Going from green to red is called “browning out”.

Is that the origin?

I thought it was an analogy to the electrical problem: flickering lights due to high demand.

That is not where the term comes from. Lights out -> Blackout (WWII, to stop overflying aircraft from having easy targets and to disrupt navigation). Reduced voltage on the grid -> lights go from white to orange and eventually to brown, not quite a blackout -> brown out.

Don't know the origin, but with no technical background past using Linux, I only ever heard of brownouts in contexts of failing (often 3rd world) electrical infrastructure. Mostly Africa and South America (don't mean to offend anybody living there, I know they're vast continents with many rich/infrastructure-stable countries too).

Origin is the electrical grid overload which caused incandescent lights to literally "brown out", as has been mentioned here.

Later is was coopted to mean any problems with power supply not including outright drop to zero-zero/disconnections. cf microcontroller brown-out handling, also mentioned above.

Then later it seems it was generalized to mean sort-of-non-terminal problem with supply of most anything.

Very odd to call it a 3rd world phenomenon when California calls it a normal day.

The word seems to slightly predate WWII.

The OED reports that the disrupted-electrical supply sense of blackout was first used in 1934; the air-defence one (no light) in 1935. However, the OG use seems to be in the theatre, where the lights are shut off during set changes (1913, probably earlier).

Brownout does seem to be a WWII-era term, but more related to conservation/shortages than air defence.