Louie is the nicest of the trio. He is gentle, carefree, laid-back, and notices things others miss easily, showing a particularly creative thinking. Louie is not very loud and disobedient like his brothers. He can sometimes be absent-minded and a little bumbling, but when it's needed is shown to be just as clever as his brothers. In his teenage appearance in Quack Pack, Louie appears much like a hip-hopper a contrast to his brothers, Huey and Dewey's casual appearance. He wears a green tank top and dark green pants. He also wears a cap on his head.
While Louie wore his now-trademark green shirt in the earliest of cartoons, he sometimes sported a yellow shirt.