No matter what she says, it won’t change the fact 
I personally like black color and I have 3-4 our of 8-9 shirts that are black. Of course I also have black dress pants and suits etc. As for wearing it on weddings, if the grooms can wear it, why are women putting self imposed restrictions on themselves? Why can’t they wear black dresses? Who cares what the community thinks, what matters is that you are happy. Bad luck associated with black is just superstitions.