Since the fashion cycle has gotten so wonky, and since the advent of air-conditioning, and because of who-knows-how-many other reasons, quite a lot of dresses that no one in their right minds would wear in July are now sold then. Which means that by Labor Day, they are all on sale.
Take this one for instance, at Bloomingdale's, in a small range of sizes (although that range includes 24W!) going now for $69-79. It's all silk, and it's quite elegant. And yes, it also comes in black. (Click on the image to visit the catalog page.)
This is a perfect holiday-party dress for those of us who think bare arms and shoulders in December is a great way to catch a cold, and/or folks who hate managing a drippy shawl, or who just want to look a little more covered-up. It's so rare to find a holiday-party dress that's not bare and still looks witty and dashing and elegant — something that is the female equivalent of the tuxedo, in fact, which I suppose is why this one works!
I think I would wear this with huge cloisonne beads or very large cloisonne cuffs, and high heels — as high as I could manage. Maybe black patent heels with a very square heel and a round (or at least not very pointy) toe, so they would look like men's classic tuxedo pumps, and a black patent clutch. And red lipstick. Definitely red lipstick.
I would NOT wear it with a pin or brooch that featured any of the following: Christmas trees, Santa, candy canes, holly, blinking lights (especially not blinking lights that were intended to represent, say, a reindeer's NOSE), or the words "Ho Ho Ho." There's festive, and then there's festooned. There's a difference.