However, let's assume you choose to ignore the traditional answer. Perhaps you see nothing wrong with removing your dinner jacket in public, or maybe you want to know that if you're in an automobile accident and are rushed to the hospital, the doctor seeing your braces will be impressed with how well they match your dinner jacket. (And, of course, you'll want to be wearing nice underwear, too.) Or maybe it's enough that you'll know which braces you'll be wearing, and dagnabbit you want them to optimally match your dinner jacket even if nobody else will know or care.
In that case, I'd vote for the ivory Barathea, with nickel. Simply because ivory and midnight blue is a splendid combination. Just as the midnight blue is a "better" black, so is ivory a "better" white. I mean, if you don't want to think of it in those terms, fine. And I admit that there's nothing wrong with the white braces. But hey, you wanted an opinion, so I've given you an opinion.
Also, I prefer nickel with the midnight blue, since with the possible exception of yellow gold, I prefer matching midnight blue with a white metal, and not a yellow metal. (Same answer if the dinner jacket were black, btw.)
So, which do you prefer, and why?