what to wear

Next weekend I am going to a wedding, the first one I have been to since my dads when I was about 8! It will be a posh do, ceremony in the Orangery and reception at the Belvedere. I am obviously stressing about what to wear, but this is the plan at the moment. I am going to wear my black french connection strapless dress that I already have. I have been assured by several people that it's fine to wear black as long as I brighten the outfit up with accessories in lighter colours. Thus I will take my (very blinging!) silver clutch bag. Now all I need to get is a pashmina in a pale colour and some silver heels. My only worry is that my outfit will look more night club then posh weeding!