Examine source code of To a quiet space....

{
  "theme": {
    "images": {
      "theme_frame": "0604-image.jpg"
    },
    "colors": {
      "frame": "#bfc5c7",
      "tab_background_text": "#f0c9df"
    }
  },
  "version": "2.0",
  "name": "To a quiet space....",
  "manifest_version": 2,
  "description": "静かな空間へ。。\n\n\n\n0604-image-●"
}