Read this: Domestic dogs often display the remnants of countershading, a common natural camouflage pattern. A countershaded animal will have dark coloring on its upper surfaces and light coloring below, which reduces its general visibility. Thus, many breeds will have an occasional "blaze", stripe, or "star" of white fur on their chest or underside.

A dog with countershading has dark coloring where?
What is the answer? (If it cannot be answered, return "unanswerable")
upper surfaces