My tendency, when matching nails to a dress is this:
Pick a colour that compliments it as your base, and use the colours that are 'in' the dress as the accents.
Why?
If pictures are taken, I don't want the nails 'dissappearing' because the hands are against the dress.
Know what I mean? Sort of a chameleon effect?
Like french on a bride. They dissappear against the dress. I hate that.
I like my nails to 'pop'. I prefer them to 'compliment' as opposed to blending in.
I would choose a different colour as a base, and then add a floral or abstract pattern in black and gold.
Or, choose your base colour, then add gold foils, with some black fliks or other 'black' bits or black lace.
etc..
hope I've made sense, and hope it helps.