I got these for my daughter and they were great untill she got them wet then they stopped changing in the sun. I am not sure why they would stop working, I would think since they are kids shoes and summer shoes that would not deter them from working. I am going to try to return them for a new pair since she has only had them for about a week before they stopped working. So I am very disapointed maybe I just got a defective pair!!!!