Examine source code of There is a bear again.

{
  "theme": {
    "images": {
      "theme_frame": "1108-kumagamatairu-hana68.jpg"
    },
    "colors": {
      "frame": "#f5f2f2",
      "tab_background_text": "#daecf0"
    }
  },
  "version": "2.0",
  "name": "There is a bear again.",
  "manifest_version": 2,
  "description": "・・熊がいる。。"
}