Basicly, matching vivid colours with black seems a little vulgar to me. But if you contrast them with white, then you get a pure modern look. I like that. Additionaly it makes the pink-orange combo look less kitchy. The stiff, perfectly tailored white blazer is the mother of the geometrical form of the outfit, and the converse sneakers are killing its puff-upness.
dress, blazer - Zara
sneakers - Converse
bag - H&M Fasion Against Aids
bracelet - Solar