Examine source code of Darkly Hallows Eve

{
  "name": "Dark Halloween",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "halloween.jpg"
    },
    "colors": {
      "frame": "rgba(66, 66, 66, 1)",
      "tab_background_text": "rgba(166, 76, 76, 1)",
      "toolbar": "rgba(66, 20, 20, 1)",
      "bookmark_text": "rgba(102, 102, 102, 1)",
      "toolbar_field": "rgba(94, 94, 94, 1)",
      "toolbar_field_text": "rgba(59, 10, 64, 1)",
      "tab_line": "rgba(255, 149, 0, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{8b8a90f8-ddc9-48cc-a940-8b234bdc648d}"
    }
  }
}