I decided to open an SR and was informed there is no way to do this. An ER has been created.

I too do this for our HCM landing page. But I am referring to the Reports and Analytics page. Once you click on Catalog, the color is the same in both Prod and Stage pods. We have 3 pods - 1 Prod and 2 Stage pods. Because we switch pods frequently, unless you look at the URL, it's not visually obvious.