The primary color of a blue whale is a deep blue, although its skin can appear mottled with lighter spots. Blue whales are the largest animals known to have ever existed on Earth, growing up to 100 feet in length and weighing as much as 200 tons. Their coloration helps them blend into the ocean depths, providing some camouflage from predators and enabling them to hunt their primary food source: krill. These majestic creatures are known for their incredible size and distinct blow, which can reach heights of up to 30 feet when they surface to breathe.