Examine source code of Iceburger

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Iceburger",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-037-b73f9b34467ba541de861f5b4c0c6316.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(69, 120, 140)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(28, 60, 80)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(37, 79, 94)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(38, 223, 218)",
      "popup": "rgb(61, 121, 158)",
      "popup_text": "rgb(255, 255, 255)",
      "button_background_active": "rgb(61, 121, 158)",
      "frame_inactive": "rgb(168, 194, 210)",
      "icons": "rgb(255, 255, 255)",
      "ntp_background": "rgb(55, 86, 97)",
      "ntp_text": "rgb(255, 255, 255)",
      "popup_border": "rgb(255, 255, 255)",
      "sidebar_border": "rgb(255, 255, 255)",
      "sidebar_highlight_text": "rgb(255, 255, 255)",
      "sidebar_highlight": "rgb(163, 244, 233)",
      "sidebar": "rgb(69, 120, 140)",
      "tab_loading": "rgb(69, 120, 140)",
      "tab_text": "rgb(255, 255, 255)",
      "toolbar_field_border_focus": "rgb(255, 255, 255)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{97d0665c-e92e-4f8e-8362-a166d71c237d}"
    }
  }
}