I'm pretty sure it's the same thing.
The FAA goes out of their way in an AC to denote closure markings as yellow X's. Whether some airports need not consider that guidance applicable because of not receiving federal funding for instance or for any other host of reasons I don't know about, I don't know. I'm not going to pretend to be "pretty sure" about something I know I don't know.
There could always be a notam that says nonstandard runway/taxiway markings. Our local airport honchos went out and painted a hold short line where there wasn't supposed to be one so we had that going for a while.
If its a private strip it may just keep uninvited yahoos away just the same.
Or maybe all you saw was some light from Venus refracted through some swamp gas.