Amazon River Dolphin (Pink Dolphins)🐬

Although Amazon pink river dolphins are famous for its pink hue, they weren’t born this way. The dolphins are actually born gray and slowly turn pink as they age. Male dolphins are strikingly pinker than their female counterparts; the coloration thought to be a product of scar tissue resulting from rough games or fighting over conquests. However, their final color can be influenced by their behavior, capillary placement, diet, and exposure to sunlight; with brighter pinks attracting more attention from the females. These river dolphins can sport markings that range from mostly gray with some pink spots, to full flamingo pink.
Fun fact: when the dolphins get excited, they can flush a brighter pink, similar to humans!

National Geographic