[LunarBerry]

10thmuse, (a bit of a late reply) we've had a yorkie that took longer for their coats to mature completely, like 2-3 years. It varies with each yorkie but on average it's around a year, give or take, but some may take about 3-4 years (at longest that I've known). Even my current girl I've noticed more silver creeping into her black saddle coat from the legs and she's two years old. It may continue or may not, but it was noticeable for me to see.