Examine source code of Gray oak.

{
  "name": "Gray oak.",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "3a.jpg"
    },
    "colors": {
      "frame": "rgba(255, 255, 255, 0)",
      "tab_background_text": "rgba(214, 214, 214, 1)",
      "toolbar": "rgba(125, 139, 168, 0)",
      "bookmark_text": "rgba(199, 199, 199, 1)",
      "toolbar_field": "rgba(112, 112, 112, 1)",
      "toolbar_field_text": "rgba(0, 0, 0, 0.58)",
      "tab_line": "rgba(82, 82, 82, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{55b35ca8-3e86-42e9-9677-e60d7dc08cf6}"
    }
  }
}