Try putting this auto-enter calculation on the field into which you are pasting this text:
TextFormatRemove ( Self )
and clear the "do not replace existing value..." check box.
That may not work, but it's worth a try.
Also try clearing the "delineate" check box in Layout Setup...
Thank you. That makes the text visible when I leave the field -- which does the job -- but I still would love to know why FMP does this in first place...
Pasting data into a field pastes both the data and any text style formatting of that data. Apparently, the pasted text includes text styles that make the text match the color of the field's background.
The auto-enter calculation removes that formatting.