Annie2

Thanks everyone for your suggestions! I'm off to give them a try and see what works best for me.  I really appreciate your help 

@firstdefence I have tried using both natural light (shooting outside) and artificial light, shooting with a Canon DSLR and a macro lens. I set the white balance for the lighting and bracket shoot to see the variations in the background, but seem to get different results even within the same shoot.  I will definitely need to practice more with shooting the images which should give me less work post-production!  Thanks for your tip on the lighting source.

Thanks everyone for your suggestions! I'm off to give them a try and see what works best for me.  I really appreciate your help 

Welcome to the Serif Affinity Forums, @Annie2.
Use the Erase White Paper filter and then add a background layer filled with white (or any colour of your choice).

Hi Annie, what lighting if any are you using to take the images and what camera?
All light has some colouration which can be shown by its Kelvin rating, depending on the light source, be it natural or artificial it will create a colour cast, pitching at around 5600 - 6000 kelvin would get you a nicer light with a lilt towards the bluer spectrum.

The selection brush w. snap to edges turned on will quickly grab the background. Then "Edit/Fill" will replace the shaded areas w. a flat color.

I'd rather use a selection and a level mask or a fill layer (if I want to keep the original file with layers).
"Erase white paper" add transparency when some colours aren't 100%, and don't erase some light colored pixels.  For example, when I use it I need to add a white background behind the logo's parts and clean up the background before exporting with transparency.