2 and 3 are better designed, but the colorsdon't feel "just right":
#2-Mixing any choice color with a metallic silver could bring out the interesting 3D shapes in this dress. Certain parts look like scales and other parts, closer to the sides, look like they were inspired by quantum theory.
#3-The shape of the dress is very eye catching. The color makes a picture of a fowl (i.e. a wild chicken) pop up in the back of my head..not the best color association.