Only effective when the stand is empty - no point covering up the seats then standing in front of them!
Needs a clandestine operation - perhaps there 's an Owl or two working on the roof who can accidentally splash some paint about in their lunch break...
In episodes of Dream Team, Sky used wide angle footage of Wednesday away matches when we had the purple kit to represent the mighty Harchester United.
On a different note, Roy Hattersley's Spitting Image puppet invariably wore a Wednesday scarf.