Hi, and welcome, the green is indeed how it is
I just discovered that! In the tutorial for Screen4, Art (I think it's Art) toggles through all the screens in 1024.set. The Settings screen is beige like the rest, so I just assumed it was some kind of error in my installation.
Anyway, I played around in Screen4 and discovered that the image used for the background is indeed green. I'll just change the image from green to beige for now. But I will also be making my own screen soon!