If you want a black background on your iPhone 7 (or 6/6s etc.) and chose a black picture you will still see the folders and the dock being grey.
If you want, you can download this black special picture:
You can also download it from here: [URL]http://heyeased.weebly.com/black-in-black.html[/URL]
Then select it as a normal background (no 3d effect) and everything will be black.
If you also want to remove the letters of your folders, to make them appear blank, just get this app [URL]https://itunes.apple.com/fi/app/unicode-pad-free/id368394740?mt=8[/URL] and copy an empty space as a letter and paste it for your folder names.
If you want, you can download this black special picture:
You can also download it from here: [URL]http://heyeased.weebly.com/black-in-black.html[/URL]
Then select it as a normal background (no 3d effect) and everything will be black.
If you also want to remove the letters of your folders, to make them appear blank, just get this app [URL]https://itunes.apple.com/fi/app/unicode-pad-free/id368394740?mt=8[/URL] and copy an empty space as a letter and paste it for your folder names.