Examine source code of miku append

{
  "theme": {
    "images": {
      "theme_frame": "append-head-s.jpg"
    },
    "colors": {
      "frame": "#d9d9d9",
      "tab_background_text": "#1a1a1a"
    }
  },
  "version": "2.0",
  "name": "miku append",
  "manifest_version": 2,
  "description": "Hatune Miku Append"
}