statement necklace for a v neck dress

[Autumn2014]

I'm going to a black tie event. I have a full length plain black dress with a v neck. It's a Grecian style with ruched bust line leading up to wide straps. It has a black sequin band under the bust. I also have a fabulous black sequin jacket as a cover up. My shoes will also be black, or maybe black with gold heels. I'm taking some flat black sparkly ballet flats to change into as the evening progresses- I'll be 20 weeks pregnant!
I don't know whether to get something colourful, or if that would look a bit odd in isolation with the all black, something sparkly, or if the neckline is busy so to keep it simple. I've done a search and the dress is a bit like this but without the side split.
and this is the jacket.

www.asos.com/ASOS-Curve/ASOS-CURVE-Grecian-Maxi-Dress-With-Sequin-Band/Prod/pgeproduct.aspx?iid=3007071
direct.asda.com/george/womens/coats-jackets/sequin-jacket/GEM385936,default,pd.html
I've found a link to the actual dress!
www.jojomamanbebe.co.uk/sp+black-maternity-maxi-dress+B4778
thanks in advance

[Pantsalive]

If you're going for the shoes with gold heels, how about something like this V-shaped torque?

[Pantsalive]

Or this one looks good, although it says chrome but looks gold:
necklace&ref=srgallery13 etsy

[Autumn2014]

thanks for the suggestions. they look lovely but I'm not sure I like the hard rigid type necklaces.