I recommend you to use this dark and purple color as your Oppo R11 background. An abstract background with HD resolution, this background has 1080×1920 pixels which perfect for Oppo R11 screen. Just download and save this background in original size and set this picture as wallpaper.
Oppo R11 was released on 2017, June. It has many advanced features including: 5.5-inch screen size, 20MP camera, 6GB RAM, 3000mAh battery and many more.