How do I change the desktop background color for the part of the desktop not covered by wallpaper?

[cristanf]

For example, I have a fit or centered picture as my wallpaper. I would like to change the background color around the picture. Is there a way in Windows 10 please?

 

[Codename]

Hello cristanf!

From what I am understanding from reading your question, it seems as if you are not putting in a wallpaper that matches the resolution of your monitor, and with this black bars will appear on your wallpaper. Unfortunately there is no way to fill in that blank area with a color that is built in with Windows 10, though I may have some solutions.

Solutions:
-Change your wallpaper to "Fill" to get your entire wallpaper to fill the spaces you are having. You can do this by right clicking on your desktop, click "personalize", and choose "fill" in the "choose a fit" tab.
-Find a wallpaper that matches the resolution of your monitor. To find your resolution, right click your desktop and go to "display settings". Scroll down and click on "advanced display settings", and your resolution should come up first under the "resolution" tab. You can search for that resolution on Google and some options will come up, depending on what size of monitor you have (Example: 1920x1080 wallpaper).
-If you have a specific wallpaper in mind, you can change the size of the image to fit your monitor by using any program that allows you to do so (Examples include Paint.net, Photoshop, etc.).
-On the topic of using these programs, if you just want a background color behind your image, use your monitor size again when using these programs, insert and center your image, and use a fill tool to create a background color for your image.

I hope I helped!

 

[oscamp08]

If vertical black bars appears then clean your desktop, take an screenshot, open paint, paste the image, use the color you want for the black area, then save the image with full size, and put it as wallpaper.

 

[cristanf]

Many thanks! Both your answers were very helpful.