What color should a leopard gecko's toes be?

I have a leopard gecko that I got from a pet store 10 months ago. I know that you are supposed to pay attention to it's toes to make sure that he shed the skin off of it all the way. When I was holding him today I noticed that its toes are grey. Is that normal? I soaked his feet in warm water and tried to see if its skin that can be peeled off. If it is I have no clue how to get it off with out hurting its toes.