Pictures would certainly help, but its not uncommon for colours to change somewhat.
When I brought Bacca home at 8 weeks, he was a light brown colour and covered in longer dark/black longer hair.
Very quickly he shed off most of this fur and developed a light red shade with only a smattering of dark guard hair.
Predominant markings, however, don't generally change much. So if pup has a large white collar at birth, that will continue.
Here's Bacca at 3 years, 16 weeks and at 10 weeks. You can see the colour changes subtely, but its mostly consistent. The telltale patch on Bacca is the sable band on his left foreleg, just below his shoulder. That has been persistent from Day One. You'll also notice at 10 and 16 weeks Bacca had a dark band down his back which now is virtually gone.