What you are describing shouldn't be possible . Could you upload an example to imgur and share it here? Watch out not to have any personal information in the screenshot.

I noticed that if you didn't select a background source, the background size option might not have been showing. If that was set to "fit" it could be that the background colors were shown left/right or above/below the image. I uploaded a fix for that with my translation update.

If you still have the problem, see my post above and I will try to help out.

I would love to do that but I'm not sure how to take the image. The back ground source was unselected because I was messing with it and didnt reset it. My bad on that part. Is there another update that I need to do to have access to other settings? Sorry for all the trouble

No new updates; The update I mentioned went online on sunday when I posted my reply. There are no other background options in this wallpaper I can think of that might have influence on what you saw.

As for the problem; The only thing I can think of was either that it might of been a PNG image with transparency, or it was the background size option that was set to "fit" which might cause bars. The colors are applied to an element behind the images at all times, so to see the background colors there has to be some way for it to show through/past the image. Unless there is some kind of bug that I am unaware of.

If you manage to get it again, I realized there is an easier way for a screenshot. WE has an option to make one if you click on the icon in the tasktray. There is a "take screenshot" option. You can then upload it to steam and then share it here. Just remember to avoid any private information you might have on your desktop when taking the screenshot. Either by closing programs or if you have folders with peoples names ( like some of my family like to do ) you could move those temporarily.

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As for making screenshots normally ( wrote this before I remembered WE has a take screenshot option )

If you have it again. A way to create a screenshot of the desktop would be:
1. hide all windows
2. press print screen
3. open MS paint
4. press ctrl + v to paste the screenshot into paint
5. save it :)

Print Screen will make an image and put it in your clipboard ready to paste into any software able to accept images. You can also use Alt + Print Screen to only take an image of a specific window.