Examine source code of Playful Cats

{
  "name": "Playful Cats",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "0.jpg"
    },
    "colors": {
      "frame": "rgba(229, 230, 232, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(224, 199, 199, 1)",
      "bookmark_text": "rgba(0, 0, 0, 1)",
      "toolbar_field": "rgba(222, 126, 126, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{30eb7a31-e56a-4f11-8a16-8bd14b1f00a7}"
    }
  }
}