I went "shopping" at Rodeo Drive last year, I had a blast. I'm not rich enough to actually buy Chanel or Dior clothes, but that didn't stop me from trying things on. Of course, it helps if you speak French...
Enter a store, act as if you're there every day, have some fun, and then tell them you don't like the colour!
PS: I would have bought those sunglasses at Dior though, if they would have had the right colour. Really.