Examine source code of The Bat Children

{
  "theme": {
    "images": {
      "theme_frame": "firefoxpersona.jpg"
    },
    "colors": {
      "frame": "#ffffff",
      "tab_background_text": "#1a25c7"
    }
  },
  "version": "2.0",
  "name": "The Bat Children",
  "manifest_version": 2,
  "description": "Its the batman kids!\n\nFirst Robin: Dick Grayson\nSecond Robin: Jason Todd\nThird Robin: Tim Drake\nFourth Robin: Damian Wayne"
}