Go to the scene where Aragorn, Gimli, and Legolas have just encountered Gandalf, The White for the first time. He leads them out of the forest, and whistles for his horse, Shadowfax. While the horse is running towards Gandalf, the camera cuts to a side profile of Gandalf. His robe is raised a bit, and if you look closely (you may have to zoom in if your DVD player has the capability) you can see that Gandalf is wearing white Chuck Taylor high top Vans.