I realised after I posted that Swissair had retired their MD11s, I think by gradually replacing them after the crash of Swissair 111.
That’s what I thought, but it’s the one L-1011 that could conceivably be repainted in TWA colours, even though I couldn’t find anything about it having been done. It seemed really unlikely that they would have brought it up to airworthiness standards, since it’s intended as a static display, but I could imagine some sort of flight to a maintenance/overhaul place to get it looking like they want it. Just seemed very unlikely - and very expensive - though!
I guess one other possibility would have been the removal of an L-1011 from storage in order to ferry it to Africa/Middle East/ wherever for a new operator, but having looked at the list of aircraft in the link I posted, it seems like pretty much every single one of the airworthy ones has a blue tail anyways!