White Spot on Black

Question
Some miniature and toy poodles who are black will have a spot of white on their coats, usually on the chest at birth but the hair grows in pure black. The white spot is gone after the first haircut. The skin is uniform color.
I notice the color conformation standard for poodles is "at the skin."
I have found this to be common in blacks lately but does anyone know how to tell which puppies/poodles are "masked" on the chest and which are truly mismarked? If some of the white hair grows in "black at the roots"..will the entire patch turn black or is that just a matter of "wait and see?

Answer
Hello MM,
Most of the time, if a dog has white spots that aren't permanent, they will be mostly in the chest area and around the feet.  If its going to be a true Mismark, the spot will be larger and will remain after the puppy gets his adult hair (in most cases around 9 months to a year).  
You will see, as you stated above, that the base of the white hairs on a spot that isn't permanent will be dark or black near the skin.  

I hope this helps some.  If you have other questions, please feel free to ask.  

Thanks for using AllExperts.com,
Kim