Does this mean the colors remained gray even when you first completely removed the app from the app switcher and restarted the app? And it only went back to normal after a few launches?
Do you have the Cloud Sync enabled and if so, did it sync after you launched?
How often did you had to restart the app until it was back to normal again?
I just spent another 2 hours, tryng to reproduce this issue, but without luck. Any more detailed context information about this issue would be much appreciated. E.g. what action did you do in the app exactly before the colors went grey?