Examine source code of P4 izanagi

{
  "theme": {
    "images": {
      "theme_frame": "P4izanagi.png"
    },
    "colors": {
      "frame": "#ab9f9f",
      "tab_background_text": "#dddeb6"
    }
  },
  "version": "2.0",
  "name": "P4 izanagi",
  "manifest_version": 2,
  "description": "テスト的な意味で作りました"
}