Restore the previous theme in Google Chrome

One of the improvements introduced by Google Chrome compared to other browsers was the ability to install themes and extensions quickly, without restarting the browser. But as extensions evolved and gave birth to apps, themes were somewhat ignored. Even if they are included in the Chrome Web Store, you cannot manage them there or see a list of previously installed themes, like you can with extensions and apps; nor does the browser itself offer a manager for themes like in Firefox. They are not logged in the download manager either, even though to install the theme you will download a file. So if you reset the theme and want to get it back, you’re basically out of luck if you didn’t at least write the name down or bookmarked the page where you found the theme.

But since the theme was installed on your computer, some trace should be still available, right? It turns out you can retrieve the ID of the last used theme, but it’s not a very user-friendly solution. To do that, you need to follow these steps:

• Open Chrome’s installation folder and search for the subfolder ‘Extensions’ (Under Windows, the easiest is to right-click the Chrome icon, go to ‘Properties’ and click ‘Open File Location’). For example, mine is
  C:\Users\user\AppData\Local\Google\Chrome\User Data\Default\Extensions;
• Here you will see a list of subfolders, their names a long string of letters – the ID’s of your extensions, apps, scripts and theme. Unfortunately there is now way to tell from these ID’s which one is the theme (they are probably generated randomly), so…
• Open a subfolder and look for the file manifest.json. It contains basic information about the extension like name, type and version. Open this file in a text editor and check the name and type. Repeat this until you find a manifest-file with the type of "theme" like in the screenshot below.
• Copy the long string of characters making up the name of the containing folder – the theme ID – and use it to form an URL in this format:

  https://chrome.google.com/webstore/detail/<themeID>

• Visit this address in Chrome and it should point directly to the page of the theme in the Web Store.

Keep in mind that this only works with the last used theme and only as long as you don’t install a new one. As soon as a new theme is installed, the folder of the old one is deleted. It seems Chrome is somehow hardwired to use a single theme regardless; I doubt even an extension/app would have the permissions to change this behavior.

Another solution would be to search your browsing history for something like “theme web store”, as these terms are always included in the title of pages from the Chrome Web Store. Of course, this only works if you installed the theme recently and haven’t cleared the history since. Hopefully the Chrome/ium development team will find the time to add a theme manager to the browser sometimes in the near future.

P.S. A great resource for Chrome themes is – ironically – this MyOpera page. This is the author of the theme I am currently using, Clouds.