Examine source code of NF - Clouds

{
  "name": "NF - Clouds",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "Border.png"
    },
    "colors": {
      "frame": "rgba(40, 50, 55, 1)",
      "tab_background_text": "rgba(133, 155, 169, 1)",
      "toolbar": "rgba(0, 0, 0, 0)",
      "bookmark_text": "rgba(28, 121, 147, 1)",
      "toolbar_field": "rgba(61, 67, 69, 1)",
      "toolbar_field_text": "rgba(163, 163, 163, 1)"
    }
  }
}