Those pale green and yellow colors really blend well, with the dark, somber backdrop, and does its job in reminding us that this is a pond/swamp, not a sparkling ocean. She's adorable, overall, which makes her bloodstained ensemble all the more creepy, I think.
Also, I love that you made her a bride; it reminds me of a chapter I once read in a book, dedicated to studying the cultural influence of mermaids, as well as retold folklore involving them. It said specifically, that not all drowned victims became rusalki, and that a rusalka was the spirit of a woman who purposely jumped, to save herself from a lifetime of marriage. Well, something close to that.