Examine source code of Winter World

{
  "name": "Winter World",
  "manifest_version": 2,
  "version": "4.0",
  "theme": {
    "images": {
      "theme_frame": "HCustom.jpg"
    },
    "colors": {
      "frame": "rgba(159, 187, 214, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(159, 185, 214, 0)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(159, 185, 214, 0.08)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(0, 0, 0, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e3ced388-eae1-4d1b-b612-61bfc15a89f1}"
    }
  }
}