When I got Winston he was around 15 weeks and looked like a scraggly little black and brown puff ball. After a couple months of having him I could see his true colors coming through. It took almost 6-7 months for him to completely turn. My Avatar pic is kinda hard to see but he is blonde and gray with a touch of tan and might I say super cute! Don't worry, your new baby will have its adult coat before you know it and you'll want another
You can always ask to see pics of the mom, dad, adult brothers and sisters to get an idea of what the coloring will be...just a suggestion, hope it helps!
Congrats on your new baby!!