This is all very very FASHION.
It has a serious Camelot vibe to it, which lends a sense of both nobility and tragedy.
The bright red is inescapably referential to love (they are quite literally dressed in the clothing equivalent of a box of Valentine candy) but also rage and blood – all of which is very Klingon.
Lursa and B’Etor established the boob window as a nod to Klingon femininity, so while I’m not a huge fan of the stye, it works contextually. The detailing is beautiful – the scalloping on the skirt front, the pattern on the bracers, the gold cord embroidery on the sleeves, the slightly different shades of red layered together, the CROWNS. And of course I love how they match.
But mostly I love imagining fans getting married in this.
I was asked on tumblr where one might be able to purchase this dress. I did a quick search, and asked around at a Star Trek cosplay forum, but unfortunately nothing came up as pre-made/available for sale. Having it custom made (or making it yourself) is the best option.
I’d suggest starting with a medieval gown such as this (high end) or this (cheap) and altering it to look like Jadzia’s dress. It’s not going to be a quick or easy process but at least you wouldn’t be starting from scratch.
If you or someone you know is willing to create this, please do let us know!