The wall on the purple wheel (an attempt to get the wheel for HD) was purple with a mix of the late 1970's-1988 wall with small Pricedown dollar signs and one large Pricedown. The purple on the wall was too much like the Season 36 SD turntable wall. The new red wall fits well with the HD set's door and turntable.
Just to be clear: What happened is they started with the design seen here, then they changed it to the purple wheel, then for one episode, they used the wheel used in the Las Vegas show, then they went back to the wheel design shown here.