I'm going to do this the way I do when I teach in law school:
Below are two bikes. Which one has blackwall tires and which one has whitewall tires?
Seriously, I understand the confusion because whitewall tires have a white strip, but so-called "blackwall" tires are all black- no stripe of any kind. Adding to the goofiness is all-white tires (not called "whitewalls") all red tires and gum wall tires.