Pick up any number of powerful items (I do this mostly in chaos 1 trials).
Look at inventory.
Usually six powerful items are affected by this bug.
(Side-Note: My friend that I play with does not have this bug. He plays on Windows as well)
Expected Results: I would want powerful items to be back to normal green back-drops. It is very misleading when you look through your inventory and see this bug happen.
This is a somewhat known issue with the rarity data being held in individual bag slots. The worst offenders for this tend to be pets. So, sometimes as you move a legendary pet around your bags, more and more slots will show items as legendary.