How to tell livery from trip

Today I saw a SWA plane inbound to Austin. It had a livery I hadn’t seen before. The tail was normal. The body was mostly white. Maybe it was the new State of Florida livery, but I can’t be sure. Is it possible to get a tail number from a specific flight and thus be able to look for pictures for that tail number? If I click on the photos link at, for example this page:

flightaware.com/live/flight/SWA8 … /KDAL/KAUS

I get general photos for the model of plane. Furthermore, although I can see where to enter a tail number, I don’t see where one is displayed for a historical flight like the one above.

I don’t know if that’s the plane. I didn’t record the time it flew over. There was a lot of air traffic at the time, so there are probably a bunch of possibilities. I’m guessing the flight time was somewhere in the 1-3 hours ago range. I really should have noted the time.

P.S. I see N945WN has the livery I mentioned. I thought I’d enter that and see if any flights came in to Austin today. There are no results at all. I guess flightaware doesn’t match up tail numbers with trips for airlines, probably because they can swap equipment at will, basically. Am I right?

Southwest doesn’t provide the tail numbers like some other airlines do, I keep an eye out for this one from United flightaware.com/live/flight/N475UA