HOWTO: White Background Video

PE 2021 in Expert mode on a WIN10 PC...

I know that via Project Assets & New Item / Black Video that I can insert a black video into the timeline but how can I insert a white video?

I have almost completed a training video comprising numerous slides & a few video clips all with voice-over.  I want to insert a JPEG of a 1-page document & then zoom in (Pan and Zoom) to various parts I am describing.  However since the document is A4, when I add the graphic to the timeline there are black vertical bands to the left & right (of course). 

How can I replace these bands with white?  If I could put a white video on Video 1 & have the graphic on Video 2 I'd be OK (I hope).  But how to get white video?  Or is there a simpler method?

All advice gratefully received.