Sunderland issued an apology to their loyal supporters yesterday.
The Championship side are taking on local rivals Newcastle United in the FA Cup.
Magpies fans have been allowed to redecorate parts of the Stadium of Light in black and white, as they took over the club's corporate area.
Several signs mocking Sunderland and their supporters were put up and shown on social media.
The club then said in a statement: Sunderland AFC acknowledges that a serious error in judgement was made in relation to Black Cats Bar earlier this afternoon.
We apologise to our fans for the understandable concern they have fairly voiced in response and this sentiment is shared by the Club's Ownership Group and Board of Directors, who have requested an immediate review is undertaken to determine how this process unfolded.
A direct decision has also been taken by the Ownership Group and Board of Directors to return the space to its original state and we once again apologise to our supporters that this was not addressed sooner."