Longer white hairs should be ticked across each side of the body. There is also white in the form of a triangle at the nape of the neck, white inside the nostrils and ears, white circles around the eyes, white on the belly and inside of the legs, and white under the tail.
This is the breed. There is also a variety (color) called Silver Marten that is found in a few different breeds. They are, however, a separate breed, and they should not be crossed together.