Examine source code of Smiling Friends

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Smiling Friends",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png",
        "images/1.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top",
        "right center"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat",
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(0, 0, 0, 0)",
      "toolbar_text": "rgb(215, 255, 200)",
      "frame": "rgb(249, 37, 222)",
      "tab_background_text": "rgb(175, 253, 255)",
      "toolbar_field": "rgba(255, 255, 255, 0)",
      "toolbar_field_text": "rgb(255, 211, 251)",
      "tab_line": "rgb(239, 118, 197)",
      "popup": "rgb(255, 255, 255)",
      "popup_text": "rgb(140, 140, 140)",
      "icons_attention": "rgb(0, 255, 191)",
      "icons": "rgba(255, 255, 255, 0.97)",
      "popup_border": "rgb(243, 255, 0)",
      "sidebar": "rgb(204, 242, 144)",
      "tab_selected": "rgb(0, 0, 0)",
      "toolbar_bottom_separator": "rgba(255, 255, 255, 0)",
      "toolbar_field_border_focus": "rgb(243, 255, 0)",
      "toolbar_top_separator": "rgba(61, 21, 255, 0)",
      "tab_loading": "rgb(239, 118, 197)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{38181aff-35f9-493a-94d7-a6ba6053ca06}"
    }
  }
}