Is "stor kjole" a way of describing a ball gown? Else it sounds like the queen is wearing ill-fitting (or ugly) clothes.
Stor kjole is not some clever rewriting of ball gown or anything, but I'd say it wasn't a very nice dress if the only thing they managed to say about it was "big and green" (maybe she's wearing her dress uniform?!)
For some reason, I have an image of WAY too many ruffles. http://fashionor.org/Panama-City-Panama-Beaded-Decorate-Bust-Green-and-Black-Ruffles-Layered-For-2013-Quinceanera-Dress-Style-QDZY336FOR-goods-11835.html