I've always liked military-inspired style and with it trending right now, it's a good time to take some brass-button inspiration and get your wedding in-line and at attention… okay that was a pretty lame play on words, but seriously, this could look really awesome :)
(A bit dramatic, but inspiring none the less)
When I started Googling I was surprised as how uncommon this seems. Therefore, it's a lot easier to find amazing military style coats and dresses if white isn't your preference :/ That being said, with a little digging and creativity, there's a lot of inspiration to be had.
Take the Princess of Style herself, Kate Middleton, in this lovely from Reiss which does happen to be white:
And look at this pretty little number.Very military but very feminine by Alexander McQueen:

