I'm not quite sure why Travis has a fascination with zinc oxide but I speculate it takes him back to his childhood- I mean, he IS a child of the '80s from the east coast. He even had the white Don Johnson jacket to go with the zinc.
So imagine his delight when he stumbled upon a three-pack of zinc oxide. He talked it up and Adaline was so excited to have a pink (her favorite color!!!) nose, but he couldn't quite convince me to have a green nose. Sorry, Charlie, maybe next year :)