Personalizing your computer with a new background or theme is one of the first things users do when they set up their computer for the first time. Chrome OS is no different. To customize the background and theme on your Chromebook:
To change the background image
If you select a background image to use on your Chromebook, you can choose from a variety of pre-installed images or images Wallpaper app stored on your computer.
The first thing you want to do is open the Wallpaper Picker. Right-click or double-click anywhere on the desktop. Then click "Set Wallpaper".
a new window, and you have several options for your new background. Select one of the categories on the left side of the window and then click on one of the many images on the right to set it as wallpaper.
 Clicking "Daily Update" at the top of the image selector changes your desktop wallpaper to a new image at the beginning of the day. This is ideal for those of us who are often bored looking too long at a picture.
If you want to use your Chromebook yourself and do not want to use any of the preloaded images, select "My Images" at the bottom of the list the left side. Then, like us, select a photo from the list provided
. Sometimes the pictures saved on your computer may show. You may be slightly stretched or truncated due to conflicts in the resolution between the image and your ad. When this happens, scroll up and select either "Center" or "Center Trim." Depending on the resolution of the image, it may be displayed in the center of your desktop with black borders, or stretched or truncated
Changing the theme
Changing the theme on a Chromebook does not change the look of the OS at all Instead, the look and behavior of Chrome changes for each of the offers in the Chrome webshop.
RELATED: Adding and Removing Designs in Chrome  The easiest way to install a theme is to start Chrome and go to the Chrome Webshop for fun and exciting new themes to improve the selected, shabby standard design. You can also go the long way by navigating to Settings> Appearance> Browse Themes.
Now that we've opened the Chrome web store, you can use the search bar and category selector (although only the two search for creatives options are Google and artists) or rating.
When you find a theme that matches your mood, click it Go to the topic page.
Click Add to Chrome to add it to Chrome.
When you add a theme to Chrome, it syncs to your Google Account. So, if you sign in to Chrome on another device, the theme syncs to that device as well. You can prevent this by going to Settings> Synchronize and disabling switching between topics.
Once the theme is installed, the "Add to Chrome" icon turns into a grayed-out "Added to Chrome" icon.
The theme seamlessly applies to Chrome without you having to restart it.
Removing a theme
If you want to install a theme other than Chrome, just follow the steps above. However, if you no longer want to install a theme in Chrome and want to return to the classic theme, you'll need to restore the default Chrome theme through the Settings app.
Open the Settings app and scroll to the Appearance heading. Then click Reset to Default next to the Browser Themes option.
If you're already in Chrome, click the menu icon, then Settings, or type
chrome: // settings / into your address bar to get there. 
. Scroll down until you see the Appearance section. Under Designs, click Reset to Default. "width =" 650 "height =" 118 "src =" /pagespeed_static/1.JiBnMqyl6S.gif "onload =" pagespeed.lazyLoadImages.loadIfVisibleAndMaybeBeacon (this); "onerror =" this.onerror = null; pagespeed.lazyLoadImages.loadIfVisibleAndMaybeBeacon (this); "/>
Since Chrome only tracks the last installed theme, you do not have to remove other themes, so clicking on the button will do everything the way it was in the beginning: gray and white.