Examine source code of Grunge Impact

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Grunge Impact",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg",
        "images/1.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top",
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "repeat",
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(0, 0, 0, 0.62)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(227, 30, 57)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgba(255, 255, 255, 0.61)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(94, 178, 206)",
      "popup": "rgba(0, 0, 0, 0.79)",
      "popup_text": "rgb(227, 30, 105)",
      "frame_inactive": "rgba(0, 0, 0, 0.57)",
      "tab_loading": "rgb(94, 178, 206)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{59129a6b-d6a6-452b-a5a6-df49f45ad943}"
    }
  }
}