Examine source code of GREN2

{
  "name": "GREN2",
  "manifest_version": 2,
  "version": "7.0",
  "theme": {
    "images": {
      "theme_frame": "2b.jpg"
    },
    "colors": {
      "frame": "rgba(46, 92, 8, 0.7)",
      "tab_background_text": "rgba(0, 0, 0, 1)",
      "toolbar": "rgba(189, 189, 189, 0)",
      "bookmark_text": "rgba(5, 5, 5, 0.98)",
      "toolbar_field": "rgba(212, 206, 185, 1)",
      "toolbar_field_text": "rgba(79, 61, 39, 1)",
      "tab_line": "rgba(46, 27, 11, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{49a7441b-d93d-400d-8d28-1e683ff183ec}"
    }
  }
}