Examine source code of Duck Donut

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Duck Donut",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center center"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(231, 240, 245, 0)",
      "toolbar_text": "rgb(248, 112, 140)",
      "frame": "rgb(218, 233, 94)",
      "tab_background_text": "rgb(225, 255, 241)",
      "toolbar_field": "rgba(120, 142, 14, 0.32)",
      "toolbar_field_text": "rgba(219, 247, 197, 0.88)",
      "tab_line": "rgba(157, 230, 173, 0.71)",
      "popup": "rgba(150, 203, 103, 0.37)",
      "popup_text": "rgb(10, 112, 0)",
      "button_background_active": "rgba(159, 179, 58, 0.32)",
      "icons": "rgba(110, 169, 57, 0.69)",
      "sidebar_highlight_text": "rgba(136, 164, 9, 0.78)",
      "sidebar_text": "rgba(178, 199, 81, 0.32)",
      "tab_loading": "rgba(157, 230, 173, 0.71)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{339e1251-afc6-4783-902b-0329c428a0f4}"
    }
  }
}