Is this dress OK for a wedding reception?

This is a evening reception at Ritz Calton half moon bay. The groom, who invited me is a high school/college friend of mine. He is probably the first few people I met after I came to US and still kept in touch.  Well, not really, we lost touch, then reconnected after bumping into him at a officemate's wedding.  My officemate happens to go to the graduate school with the groom.  Small world.

The guests I will know are all engineers and are normally very casual.  In fact I don't recall ever seeing them dress up other than interviews back 15 years ago.   The bride's side of guests are unknown.  I ask the groom what the dress code is and he said there is no dress code, but people might dress up just because it is Ritz. Oh, well, he is not much of help. The bride seems to really have a thing for Kate Spade.  Lot of Kate Spade frames on the gift registration list and they are $100-$200 and with almost no design on them. Why buy a boring traditional silver frame for more $100 these day when you can get a fancy digital frame for the same amount. Then again, I am not a very classy person.

So is it OK just go like this? Maybe I will change my usual necklace to something more sparkly? But I can't think of other idea at the moment to accessorize it.  Did the sweater made the dress even more casual?  What other things can I do to fancy it up? I really want this one to work....