What practical purpose did the pure white coat serve for the Tatra Shepherd ancestors?

Answer

To make the dog easily distinguishable from dark-coated predators.

The white coloring was a strategic selection pressure allowing the shepherd to easily distinguish the dog from dark-coated predators, such as wolves, especially during poor visibility.

What practical purpose did the pure white coat serve for the Tatra Shepherd ancestors?
OriginDogshepherdTatra