When I remove your fork from my system the status bar and notification bar for my home screens are still red. My assumption would have been that when I removed your fork, the red would be gone too but that is not the case.
I am simply trying to understand more how it works so I can recover from the situation in the best way.
I know you wont know the answer to the second part of the question but perhaps someone could confirm that on removing this K9 fork from their system the red status and taskbars were also gone, I would then have a better idea where the problem lies.
I hope I have explained myself a little better and thanks very much for your feedback.
There must be another problem with your android, or your launcher.
The notification bar color changing has nothing to do with this version of K9-Mail. It's an android feature.
Something similar should happen with other apps, too.
What about going to recovery and cleaning cache and dalvik/art?
Perhaps this could help...