I didn't learn much from reading this article. Questions linger in my mind, for example: What are the CIE XYZ coordinates of each colored square? What is the spectral distribution of each square? How were the colors chosen?
These aren't appropriate questions for the birthday party
You sound like you actually want to just generate them yourself using ArgyllCMS `targen` and `printtarg`.
The Wikipedia article is far more informative, though I'm uncertain if read the full dpreview article due to ad-induced nausea.
https://en.wikipedia.org/wiki/ColorChecker