I could not find any shoes that were quite as bright neon as Hayden's, but I think I found Jessica's. My best guess is that they are the Kate Spade "licorice too" pump in the colour "Fuxia Flouro Patent" (below). They run for a not so modest $300. In my search I was looking around for some other colour/style/price variations and this is what I found:
Rachel Roy | Kate Spade | Alice +Olivia
Town Shoes | Aldo
What do you think of coral shoes?