Millwall, which normally plays in white on the road, was forced to line up in Sheffield Wednesday's yellow away kit from last year when the Lions somehow left their own at home in south London.
Millwall then managed to get its orange third kit to Hillsborough in time for the second half and changed clothes at halftime.
The visitors earned a 2-2 draw after Andy Keogh equalized with a late penalty.
Millwall manager Steve Lomas said the kit mishap was "just an honest mistake, I think. These things happen. It just added to the madness of the game."
It was Millwall's first point in four games.