OP there are some very dull, parochial opinions on this thread & some absolutely hideous 'alternatives' shown!
It's utter nonsense that black can't be worn to a wedding & that every woman must be frou frou'd up in bright garish colours.
I've attended many weddings & have frequently worn black. And noone threw stones or barred me from entering. Or mistook the entire event for a funeral etc etc
The dress you posted is not particularly my taste but I can see how it could work.
Wedding threads are generally bonkers on here & when you add it up with the equal number of threads about the many bizzare approaches to wedding receptions it makes all the angst over the 'rules of how to dress' even stranger!