Examine source code of Simple Dark Material

{
  "name": "Simple Dark Material",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "transpalent.png"
    },
    "colors": {
      "frame": "rgba(34, 34, 34, 1)",
      "tab_background_text": "rgba(255, 255, 255, 0.6)",
      "toolbar": "rgba(45, 45, 45, 1)",
      "bookmark_text": "rgba(255, 255, 255, 0.87)",
      "toolbar_field": "rgba(60, 60, 60, 1)",
      "toolbar_field_text": "rgba(255, 255, 255, 0.87)",
      "tab_line": "rgba(255, 255, 255, 0.05)"
    }
  }
}