Examine source code of macOS-Dark

{
  "name": "macOS-Dark",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "shifaaz-shamoon-sLAk1guBG90-unsplash.jpg"
    },
    "colors": {
      "frame": "rgba(45, 46, 48, 0.4)",
      "tab_background_text": "rgba(221, 229, 235, 0.7)",
      "toolbar": "rgba(64, 64, 64, 0.8)",
      "bookmark_text": "rgba(214, 214, 214, 0.86)",
      "toolbar_field": "rgba(255, 255, 255, 0.75)",
      "toolbar_field_text": "rgba(0, 0, 0, 0.7)"
    }
  }
}