Users of Peacock v2+ are using a memento peacockMementos.peacockColor that stores the color that is applied to each workspace. This has been removed in v3 and now Peacock uses a worskspace setting named peacock.color.
When a user upgrade to v3, any colors previously applied would be removed since peacock.color is not present in their workspace (because it did not exist in v2).
The Goal and Expected Behavior
When a user upgrades to v3, their existing colors applied should still work.
[scenario 1] v3 would look for a workspace peacock.color. If it exists, proceed as normal. There is no problem.
[scenario 2] If there is no workspace peacock.color, then look for the old memento. If that memento exists, write it to the workspace so the color is applied.
[scenario 3] If neither exists (which will be the case for new users), nothing will be done.