I changed my team's primary color to a user defined color using RGB. It "took" just fine everywhere, except for when my players' jerseys are displayed on things like the POG. There's a little broken image icon in the upper left signifying that the image was missing, and my player is *gasp*... naked!!

https://imgur.com/a/xoX6dyZ

It's the same anywhere the primary color is used to render the main jersey color (e.g., season preview in the magazine). When the white jersey with secondary color is used, it's fine. So it definitely seems to be related to the change in the primary color.

So I never got back with the solution here, and it might help folks. I remembered that I not only changed the primary color, I also changed the team's main logo and selected a new file name. Turns out those jerseys the game uses for the preview magazine, player of the game, etc., are tied to the logo name... they both have to be the same. So when I changed the logo to a new filename, it lost the jersey. I changed the logo file to the previous name, and it fixed the issue.

TL/DR: If you change logos for your team, make sure you don't change the file name for the logo.

And THAT is the naked truth!