Examine source code of joker vs batman

{
  "theme": {
    "images": {
      "theme_frame": "the-jokes-on-you2-copy.jpg"
    },
    "colors": {
      "frame": "#000b2b",
      "tab_background_text": "#e30cdf"
    }
  },
  "version": "2.0",
  "name": "joker vs batman",
  "manifest_version": 2
}