Welcome to YorkieTalk. It's hard to say if the hair will grow darker when it gets longer. Usually hair grows fairly fast.
Colors change as yorkies mature. My boys are 2 and 3 and have changed dramatically from their first year. Max's head is nearly all gold now and my blondie Teddy's head is darkening to gold.
Post pictures and members here may be able to give more guesses as to how your boy's hair will mature.
__________________ Kristin, Max and Teddy  |