PAX has a new theme every year. For example, 2018 merch was all falling pixellated theme that looked like The Matrix. 2019s theme was this gross slime look.
Each PAX has its own colors. South is Orange, East is Red, West is Blue, AUS is Yellow, and Unplugged is Purple.
Therefore, PAX Unplugged 2019 has purple slime.
There is a new theme starting at South next month in 2020. It appears that it’s going to be a “PAX University” theme. We’re talking like, PAX letter jackets, and that sort of thing.