Examine source code of Nord Dark Mixed

{
  "name": "Nord Dark Mixed",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "output-onlinepngtools.png"
    },
    "colors": {
      "frame": "rgba(76, 86, 106, 1)",
      "tab_background_text": "rgba(236, 239, 244, 1)",
      "toolbar": "rgba(46, 52, 64, 1)",
      "bookmark_text": "rgba(236, 239, 244, 1)",
      "toolbar_field": "rgba(236, 239, 244, 1)",
      "toolbar_field_text": "rgba(46, 52, 64, 1)",
      "tab_line": "rgba(216, 222, 233, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f9be0715-61a7-4388-a744-652d68bd6d23}"
    }
  }
}