I have decided to use a work-around as follows : - I have created a normal.dotx template alongside the normal.dotm template and I have created a shortcut to normal.dotx on my desktop. Double-clicking this launches Word and shows the pale green 'paper' colour I want. Normal.dotx obeys Windows Registry setting but normal.dotm does not.

This works fine for new documents. Also documents created using this template continue to display correctly thereafter even though the document has the same docx extension as one created from the normal.dotm template. Weird!

Documents created previously by launching Word normally using the normal.dotm template still show as white 'paper' so this work-around doe not help in those cases.

I'll consider this thread closed now.

Thanks to all respondents.