Here's a wallpaper for the iPhone XR that perfectly borders the screen in rainbow. There's a bunch of other cool wallpapers too at this website - https://heyeased.weebly.com : r/iphonewallpapers
Best wallpaper for an blue iPhone XR. : r/iphonewallpapers
iPhone XR Wallpapers - Top Free iPhone XR Backgrounds - WallpaperAccess | Iphone wallpaper, Iphone background, Best iphone wallpapers
Black iPhone XR , Dark iPhone XR HD phone wallpaper | Pxfuel