Coloring

• The blue whale was given its namesake due to its light blue color under the surface of the water. At or above the surface of the water, the blue whale looks different, with a grey mottled appearance. The underside of the flippers may appear lighter. Small ocean plant creatures or barnacles may cover their bodies. Some whales have microorganisms attached to the body, giving the underside a yellowish green coloring.
  
  

Body and Blowhole

• Blue whales have a long, slender body which is slightly tapered and streamlined throughout. The blue whale's body is quite long, as the head only makes up 1/4 of the whale's total body length. The whale's blowhole is distinctively tall, straight and can reach over 20 feet.
  
  

Fins and Head

• The head of the blue whale is U-shaped and it has a broad and flat rostrum (or upper part of the head). According to NOAA, the blue whale's dorsal fin is proportionately smaller than other baleen whales'. The blue whale's fin only measures 1 foot and its flippers are also relatively short and tapered.
  
  

Weight and Size

• As the largest mammal on earth, blue whales can weight up to 200 tons, with the weight of the average adult blue whale being 150 tons. Antarctic blue whales can reach lengths of 100 feet. According to The Whaling Times, females are typically larger than males.