Template Display Settings (Setting a Background Color)

I’m trying to set up a set of standard templates I can use for designing in Rhino (one for 2D geometry and one for 3D modeling, etc.). I was hoping to set the background of the display a different color for each template, so it would be immediately clear to me and people I work with which file we were viewing/working in, but I couldn’t figure it out. Is there a way to set a permanent display background color when making a Rhino template?

Permanent is a relative thing.
You could make two (or as many as you need) display modes with each their own background color and put your viewports in a specific display mode when saving the templates.

Background color is a global Rhino option, not an individual file property. If you want different background colors in different files (starting from templates), you might set up your templates with all the viewports having a solid-colored Wallpaper… It will still be fairly easy to break this, such as adding a new viewport to your session… Make sure the Wallpaper image is stored with the Rhino file.