Examine source code of A Country Winter

{
  "name": "A Country Winter",
  "manifest_version": 2,
  "version": "4.0",
  "theme": {
    "images": {
      "theme_frame": "7.jpg"
    },
    "colors": {
      "frame": "rgba(240, 235, 235, 1)",
      "tab_background_text": "rgba(8, 74, 3, 1)",
      "toolbar": "rgba(0, 0, 0, 0)",
      "bookmark_text": "rgba(18, 84, 3, 1)",
      "toolbar_field": "rgba(0, 0, 0, 0)",
      "toolbar_field_text": "rgba(0, 0, 0, 1)",
      "tab_line": "rgba(0, 0, 0, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{19d0d5c3-2e5e-4f84-964a-a848fa188c40}"
    }
  }
}