Examine source code of Otto (unofficial)

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Otto (unofficial)",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(43, 55, 70)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(43, 55, 70)",
      "tab_background_text": "rgb(180, 181, 181)",
      "toolbar_field": "rgb(43, 55, 70)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(247, 111, 102)",
      "popup": "rgb(43, 55, 70)",
      "popup_text": "rgb(215, 226, 239)",
      "button_background_active": "rgb(247, 111, 102)",
      "ntp_background": "rgb(43, 55, 70)",
      "popup_border": "rgb(247, 111, 102)",
      "popup_highlight": "rgb(247, 111, 102)",
      "sidebar_border": "rgb(247, 111, 102)",
      "sidebar_highlight": "rgb(247, 111, 102)",
      "sidebar": "rgb(43, 55, 70)",
      "tab_background_separator": "rgb(247, 111, 102)",
      "tab_selected": "rgb(43, 55, 70)",
      "toolbar_field_border_focus": "rgb(247, 111, 102)",
      "toolbar_field_highlight": "rgb(247, 111, 102)",
      "toolbar_field_separator": "rgb(247, 111, 102)",
      "toolbar_vertical_separator": "rgb(247, 111, 102)",
      "tab_loading": "rgb(247, 111, 102)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d85ce3e7-b587-468e-a8a2-4ec0a4cfa0c4}"
    }
  }
}