Ron, that isn't possible but consider the backgrounds purpose. It should offer the greatest contrast with the greatest range of thumbnail images that might be displayed against it. In this case PSE uses 128/128/128 in the Adobe RGB color space, also known as Neutral Gray but you may not have been aware of that. Ideally your background would never be moved from this default even if there was an easy way to do so (which would only serve to encourage it). I hope this explanation makes sense.
I'm not sure what you mean by the Bin Panel. In the Editor, it is possible to change the color of the canvas by right-clicking on it. There you can select from various shades of grey or use a custom color of your choice:
Phinny is correct about all other parts of the User Interface.
I'm talking about changing the background color that the arrows are pointing on Elements 2020 to something like shown on the screen shot of Elements 10. When spending long periods of time editing old B&W film photos, the contrast becomes hard to see the B&W photo where the light gray color on 2020 meet.