Examine source code of vampire-devil2

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "vampire-devil2",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center center"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(136, 63, 63, 0)",
      "toolbar_text": "rgb(244, 244, 241)",
      "frame": "rgb(18, 4, 4)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(245, 245, 245)",
      "toolbar_field_text": "rgb(6, 0, 0)",
      "tab_line": "rgb(243, 244, 237)",
      "popup": "rgba(255, 255, 255, 0.85)",
      "popup_text": "rgb(6, 0, 0)",
      "frame_inactive": "rgb(255, 255, 255)",
      "icons": "rgb(255, 255, 255)",
      "tab_loading": "rgb(243, 244, 237)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{0ac154ad-e76d-4555-b083-2230a5726ad7}"
    }
  }
}