I'm attempting to make my own mod which restores the normal color to the street lights, and you talked about not being able to change the color of flashpoints and hotspots,
I can definitely tell you that you can restore those somewhere in the external_cto_light_override.xtbl, I don't know which thing specifically you're supposed to edit, but I copied-and-pasted the values from external_light_override to external_cto_light_override, and going in-game I found that those events were changed back to red, despite having completed them.
I'd say you can definitely try changing up some values in external_cto_light_override and see what happens.