If you were to take a C shaped slice and overlay it onto video and then animated the color you would pretty much have it.
It would be interesting to see if they were connected somehow...
https://en.wikipedia.org/wiki/Scintillating_scotoma
I get the vivid flickering lights occasionally (in a C shaped slice as you describe), but luckily don't get the headaches.
If you were to take a C shaped slice and overlay it onto video and then animated the color you would pretty much have it.
It would be interesting to see if they were connected somehow...