I just tried to find a Virgin Trains Pendolino in O2 livery on Google and my search was very unsuccessful. Are you sure didn't have a bad dream last night, about an O2 liveried Pendolino?!
FT, I'm just joking about the dream part, but seriously, where have seen this? Living in a area where the Pendolino's don't run, means I barely ever see them in real life, sadly, due to them being one of my favourite high speed trains. So when I go to part of the country where they do run and I see one or more, I'm very happy when I do!