Changing the background color or picture in Chrome is relatively straightforward. Here’s how to go about the process. 1. Open Google Chrome and click the pencil icon in the bottom-right corner of the screen. 2. From the options on the left sidebar, select “Change Theme.” 3. Select the picture you want to use as a background from the listed options. Alternatively, you can click on “Upload from device” to use a custom picture from the local storage.