Examine source code of Winter Sky

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Winter Sky",
  "theme": {
    "images": {
      "theme_frame": "1.png"
    },
    "colors": {
      "frame": "#9c9c9c",
      "tab_background_text": "#fcfcfc"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{c94a008d-e1fd-4ed8-9029-521acfe655e7}"
    }
  }
}