We have an ongoing mystery with RED completed timelines in the Portfolio overview. At first we noticed it was related to task completion marks after the due date (easy fix!). Maybe this is still why, but…
Now, we are seeing it even if the project is completed on time, but a few tasks had been complete late.
Does this explain the reason the timeline is still showing in RED once the work is completed on the target DUE DATE?
Thanks for getting back to me, @anon99821006! These dates shown on the Portfolio List view are not updated automatically based on the completion dates on tasks within the Project. You would need to update this date manually should the Project start/end date change.
It is not currently possible to mark a Project as completed in Asana. This is a popular request in the Forum so I suggest adding your vote to this thread!