Examine source code of Downtown Seattle

{
  "name": "Downtown Seattle",
  "manifest_version": 2,
  "version": "3.0",
  "theme": {
    "images": {
      "theme_frame": "SeattleH.jpg"
    },
    "colors": {
      "frame": "rgba(18, 55, 105, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(18, 54, 107, 0)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(18, 54, 107, 0.08)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(255, 255, 255, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{dae66028-0210-44ea-8918-77c93ef947a3}"
    }
  }
}