Examine source code of OctoOcean

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "OctoOcean",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right bottom"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(2, 55, 59)",
      "toolbar_text": "rgb(180, 165, 156)",
      "frame": "rgb(180, 165, 156)",
      "tab_background_text": "rgb(2, 55, 59)",
      "toolbar_field": "rgb(180, 165, 156)",
      "toolbar_field_text": "rgb(2, 55, 59)",
      "tab_line": "rgb(2, 55, 59)",
      "popup": "rgb(180, 165, 156)",
      "popup_text": "rgb(2, 55, 59)",
      "button_background_active": "rgba(180, 165, 156, 0.4)",
      "button_background_hover": "rgba(180, 165, 156, 0.6)",
      "frame_inactive": "rgb(2, 55, 59)",
      "icons_attention": "rgb(113, 193, 200)",
      "icons": "rgb(180, 165, 156)",
      "ntp_background": "rgb(180, 165, 156)",
      "ntp_text": "rgb(2, 55, 59)",
      "popup_border": "rgb(2, 55, 59)",
      "popup_highlight_text": "rgb(2, 55, 59)",
      "sidebar_border": "rgb(2, 55, 59)",
      "sidebar_highlight_text": "rgb(2, 55, 59)",
      "sidebar_highlight": "rgb(180, 165, 156)",
      "sidebar_text": "rgb(180, 165, 156)",
      "tab_loading": "rgb(2, 55, 59)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9742292c-1914-4078-b631-7fc5b58e8e62}"
    }
  }
}