Answer:
So, I don't actually know what cells do this but if you want to think about like traits, scientists believe that it stems from their poor diet of just bamboo and lack of diversity in vegetation. Also, they don't hibernate and they move through different regions throughout the year. Because of this, they have adapted to be camouflaged in those environments at once (and all year round). Studies have shown that other than camouflage, their coloration also helps with communication. It is believed that the black on their ears is a warning to predators and their eye patches are for recognition or possibly aggressive signals.
