There is only one way to remove or delete the default wallpaper on your Samsung Galaxy Android phone: blank 1 pixel PNG file.
Yeah, it's just a simple 123 bytes image.
Here's the step by step instructions:
- Create a black 1×1px image manually or just download it from here
- Save it in your phone gallery
- Open the gallery and find that image
- Tap on «...» or look for some submenu with «Set as wallpaper» title
- Ignore the warning about image size
- Be happy with you beautiful black background with no wallpaper at all
In the end you can remove image from gallery. The background will stay black.