The so-called 'purple' trains started operation on 25.11.19 exclusively on the Paddington to Reading services. In a strange move, they are being operated by TfL (under the Elizabeth Line banner even though the actual route is over a year from opening) on behalf of Great Western Railway. At the moment they are operating on the stopping services on a regular basis and provide an interesting alternative to all things green! I think that this slightly odd arrangement is to get the sets actually operating and earning their keep as they have been delivered and stored for many months now due to the huge delay to the Crossrail line. 345006 waits to leave Paddington with the 14.16 all stopper to Reading. The well-known blogger, Geoff Marshall, was one of the first to travel on a service and gave a good account of the new trains, see....
https://www.youtube.com/watch?v=SXV95PR7pEc