Examine source code of Squirrels World

{
  "name": "Squirrels World",
  "manifest_version": 2,
  "version": "5.0",
  "theme": {
    "images": {
      "theme_frame": "ImaginationHCustom.jpg"
    },
    "colors": {
      "frame": "rgba(29, 31, 7, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(21, 23, 5, 0)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(29, 31, 7, 0.06)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(255, 255, 255, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e8434800-918f-4e45-a3ef-d820a5abd8d5}"
    }
  }
}