Most Helpful Guy
I think both dresses look very elegant and no doubt you'd look great in either of them... Personally, if I was choosing for you, I'd go for the purple one, but it's such a close call and I'd probably end up buying both of them for you to wear on different occasions! lol
Ps. If you go for the green one, I think a delicate necklace with charm would look good to hold the gap around your neck/chest area... Although the purple one would not need that as the dress comes across your neck/chest anyway...
Yeah, I would definitely go for the purple one as my first choice, and yes, you will look amazing! ;o)
Anyway, I hope you enjoy the opera!... :o)