At the bottom right of the Display window, there are 4 color pickers for foreground, background, shadow, and ground plane colors. If I make changes to these, is there a way to return to the default values (e.g. a kind of beige for background)? There is not a choice for this under Edit | Restore.

Other than doing a complete factory restore under General Preferences, IIRC, you can use the memory dots preserve your original UI. Click on the dot to remember the current setting, then make your changes. If you are not completely satisfied with the changes, just click on the active memory dot to return the saved settings.

Do you mean the UI Dots? I tried those but unfortunately it did not restore them. Undo will undo a change to the foreground or background color, but that's of limited use. I suppose I could just write down the RGB values of the orginal colors, and if I need to, restore them by hand. Seems like they should have a command to do this, though.

You know, all the years I've played in Poser, I've never known what those were for, as I usually just go into the Material Room to make changes. These are certainly much easier, that's for sure.