Grey was chosen as an implementation color because it's neither Black nor White.
and one that starts with a group of Humans making choices to go down a path of World destruction then having to come back in time to fix things up (?)
Even more interestingly, started by a Timeline break that happened in 2020. When there was a clampdown on Human Reproduction that caused repercussions for thousands of years including the eventual loss of ability to self-duplicate. (C-19?)
[Just retelling a story as it has been told. If it mirrors reality then that is very interesting.]