Examine source code of Abandoned...

{
  "name": "Abandoned...",
  "manifest_version": 2,
  "version": "5.0",
  "theme": {
    "images": {
      "theme_frame": "Abandoned1H.jpg"
    },
    "colors": {
      "frame": "rgba(38, 41, 28, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(0, 0, 0, 0)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(38, 41, 28, 0.07)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(255, 255, 255, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{64f67460-32a2-4292-b175-c65d43cfa525}"
    }
  }
}