Download picture of a nice gradient image. HD Gradient. Gradient Image is available in 360x260, 1200x630 pixels resolutions. Choose HD-Gradient.png's appropriate size/resolution from following which best fit on your device.
To download above image, click on the download button, the wallpaper will open in browser's new window, then right click on the Gradient Image image and select 'save as' to save on your computer/laptop.