This is an attractive shoe, but the teal color would best be described as green. Most of the color is green with brown and a tiny bit of turquoise here and there. The shoe seems true to length, but there's a problem with the strap adjustment. There's very little velcro area (maybe an inch or so affixed to both sides of the strap) and it wouldn't tighten enough for me. If you have a wide foot, this may not be the sandal for you either because of the limited amount of adjustment available. For a true medium foot width, you would probably be okay.
As for the arch support, the shoe bed is very flexible and you lose all but minor arch support. So, if you truly need a good arch support, I would recommend another product.