Do blue whales have long white hair or black hair on their face?

No. They may have a few bristles.

What is the color of the bristles?

Blue whales do not have hair on their faces. They belong to a group called baleen whales, and unlike toothed whales such as dolphins and orcas, they do not have hair on their bodies. Instead, blue whales have blubber, which is a layer of fat underneath their skin that helps to insulate their bodies in cold waters. The absence of hair on their faces is a defining characteristic of baleen whales. Therefore, you can conclude that blue whales do not have long white hair or black hair on their faces.