@porkpal
Do you have Coral Vine (Antigonon leptopus) in mind?
I grabbed these photos from the database. I have some little ones now and the new growth is yellowish as it first emerges (like in the 3rd photo here), then turns green. I'm not sure these are the same as in the one in question, but they might be. Are any growing in the area? It doesn't survive winter here, but I think it's considered invasive in south Texas. I've never noticed that myself. I've only seen it growing as a neglected plant on alleys and empty lots, but it does drop seed which will come up easily enough.
