What a FUN thread idea!!
I vote ombre KP on this one, though the rose shocking Kelly is a really fun choice as well for a more casual event. With the Kelly I'd probably switch out the shoes (or the necklace) to something with color, or even add a shawl with a pattern/print that pulled the golden color the dress together with the rose shocking.
To me the shape and cut of the dress is a little avant-garde so the Constance doesn't work *quite* as well as it might with another outfit.
And you need to just send the ombre Birkin to me, so that takes care of THAT.