On Slack, Wally says:
Since updating to the latest version of PanX (1916) 14 of my forms have a light blue background in both preview and the printed version irrespective of the background colour selected!
This version of Panorama X (1916) uses the tile color as the background color for printing the associated area of the report. Previous versions of Panorama X always printed with a white background color, but Panorama 6 would print using the color, so this is a “fix” to make Panorama X work more like Panorama 6.
If you want a white background, select the tiles and then change the color to white.