I get what I call magic wallpapers from a site. They work best before iOS 10.2. I stayed on 10.1.1 so I could use them. Here's the site. I edit some for color and exposure. They work on iOS 10.2, but some effects don't work. Like black folders and dock. http://heyeased.weebly.com/
The resolution of the wallpapers are very small. Some are 1x1 and 8x8.
Here's that black and blue one.