Examine source code of My Dark Theme 2

{
  "name": "My Dark Theme 2",
  "manifest_version": 2,
  "version": "6.0",
  "theme": {
    "images": {
      "theme_frame": "Unbenannt-1.jpg"
    },
    "colors": {
      "toolbar": "rgba(23, 25, 51, 1)",
      "toolbar_field": "rgba(40, 43, 59, 1)",
      "toolbar_field_text": "rgba(158, 158, 158, 1)",
      "frame": "rgba(38, 48, 71, 1)",
      "tab_background_text": "rgba(158, 158, 158, 1)",
      "bookmark_text": "rgba(158, 158, 158, 1)"
    }
  }
}