I both reset the background color and deleted and retyped the text, all with no change to the situation.

As another test, I made the text of one field bold and the white background went away in the preview. So next, I made the other fields with uwanted backgrounds that had bold text characters unbolded. This did not eliminate the unwanted background color. So, I made them bold again, and there was no change to the background. Situation is partly solved, I still have thew unwanted background in some places.