This is only related to the Grids and Background dialog. The template I have was set to have a yellow background. I changed it while in a plan view. But, when I go to layout view and open the Grids and Background, the yellow is still there, but grayed out and unchangeable. While I can still plot fine, the on-screen view of my layouts show yellow anywhere that I have objects set to use the -1 Background pen.
I think its a bug too.