That's just the default green used on WorldAs meaning 'uninhabited'. Probably could throw in some light coloration showing the areas of influence of the empires, but I imagine it's quite variable and a Westphalian depiction wouldn't do it justice, and the population density is pretty low to begin with.What's that giant space filing empire between California, Cascadia, Deseret, and Dinehtah
In terms of clients, I gave the Desereti the Hilljacks. I gave the New Mexicans their Colorado and Gila tributaries in addition to the New Age shepherds between Dinteah and the Colorado and the Pecos Cowboys, I gave the Californians "New Reno" (thought it made sense for Vegas refugees to congregate in another gambling town). I also colored the Columbian Laskans in such a way so as to imply that they're clients of Cascadia; of course, coloring Cascadia as a singular polity is a gross mischaracterization, but that is generally the trend with WorldAs and the Greeks. I figure the Cascadians are roughly similar so it's appropriate.