Is there a way to find the name of the current theme in Google Chrome?

The easiest way to find the name of your theme for Chrome is; Click on the menu button then select Settings Click on Get Themes In the upper right corner you will see your email address followed by a cog icon. Click on the cog. Select Your Apps A list of all your apps will be displayed including your theme(s)

Open file: C:\Users\Administrator\AppData\Local\Google\Chrome\User Data\Default\Preferences

NOTE: Path will vary from OS to OS... I am using Windows 7. Above file has no extension

Goto:

    "settings": (NOTE: it's inside "extensions" section){
    "[ExtensionOrApplicationId]":{

    }

....
}

Above section lists all the extensions installed on your machine for the current user.

Now search for section "theme". In this section values againt the sections "id":<ExtensionOrApplicationId> and pack points to the current theme. In general this section looks as below

  "theme": {
     "id": "ddgmdidminnkiajaonminefjlllglgap",
     "pack": "C:\\Users\\Administrator\\AppData\\Local\\Google\\Chrome\\User Data\\Default\\Extensions\\ddgmdidminnkiajaonminefjlllglgap\\1.0_0\\Cached Theme.pak"
  }

If you will simply replace value ddgmdidminnkiajaonminefjlllglgap with some other theme id and restart Chrome then the new theme will get loaded.

Hope it helps... ;-)