Instead of breaking the flow, just force-push your branch: `git push -f origin bracketcolors_v1`. You probably can even revive this one by simply reopening it, and if GitHub isn't smart enough, there's a bunch of tricks we could do to force it's hand.
This is what I did, along with squashing several commits similar [to this](https://stackoverflow.com/questions/5667884/how-to-squash-commits-in-git-aft...). I made the mistake of forgetting that I pressed the "sync with upstream" button (due to a warning I saw on the UI), and I ended up including (and taking ownership) of the upstream commits. I then panicked and renamed that branch 'bracketcolors_v1_broken' and started over again with a new 'bracketcolors_v1' branch where I cherry picked the relevant commits I cared about. But that ended up closing this pull request 💀
If any of yall can somehow reverse that mess, I owe you a beer.