I took a look around, and here are some of my shots:
Cordial Chiffon Dress
https://store.thesims3.com/productDetail.html?productId=OFB-SIM3:36015&scategoryId=11907
http://na.lvlt.sims3store.cdn.ea.com/u/f/sims/sims3/sims3store/skins/afBodyEverydayDressChiffon/Thumbnail_300x300.png
I think it's a big miss
Buona Sera Dress
https://store.thesims3.com/montevista.html?categoryId=12642§ion=UpSell
http://na.lvlt.sims3store.cdn.ea.com/u/f/sims/sims3/sims3store/skins/afBodyDOT07EvenningGown/Thumbnail_128x128.png
This one is part of Monte Vista. It's sleeveless, high neck and the botton is blue, but there's no white on top.
I hope you find what you're looking for