I purchased these exact chairs, along with the side table, and the two seater swing at a furniture store in Huntsville, Al, about 4 years ago.
The paint is not weatherproof, not sure if the current boxes still say that. But that was a selling point (and the reminded me of the metal lawn furniture my Maw Maw had a long time a go when I was a kid).
They were faded within two months of purchase from a lovely mint green, to a pale pale pale pale mint geen. They do show rust eventually on the back sides and around the bolts of course. However, all that said, they seem like they were a good solid purchase. But, as with all metal furniture, eventually with regular use and seasons (they aren't easily stored being big and metal and heavy) be prepared to eventually try to re-paint them in the two tone (if you're that brave), or repaint them a solid color within five years. They'll still be cute, but not the same as when you purchased them.