My pomeranian changed colors?

So when my pomeranian was a puppy he use to be sable which is tan with a bunch of black mixed, and its a pretty color and now hes a bout to be 2, and he changed colors when he was around 6 months but it is really starting to bother me now. Is it normal. He is more tan now and doesnt have any black color on him. Im thinking the groomers i took him to which is petco might have somthing to do with this.