Examine source code of Happy balloon

{
  "theme": {
    "images": {
      "theme_frame": "happyballoon.jpg"
    },
    "colors": {
      "frame": "#ffffff",
      "tab_background_text": "#005694"
    }
  },
  "version": "2.0",
  "name": "Happy balloon",
  "manifest_version": 2,
  "description": "以前パソコンで作成したイラストを基に作りました。"
}