I'm pretty certain they insist on a plain/solid colour background for the American Express wording, hence the panels on our striped shirts. But they certainly aren't in the minority when it comes to that as far as sponsors go.
It's clearly been based on this Nike template, different collar and shoulders but the main body is pretty much the same.
https://www.unisportstore.com/football-equipment/nike-football-shirt-energy-yellowred/69323/