It was the ex London ECW bodied Leyland Olympians that had the Arriva interior coloured panels. You can see the staircase painted as such in this photo https://www.flickr.com/photos/gjm-photog...9971505957

The MTL Olympians were known for their foistiness. Though one or two did briefly run in MTL North livery.

Only a handful of the ex Grey Green Scania N113DRB / N-C Palatine 1s ran in Arriva London livery, and those were pending conversion to single door.