Examine source code of Descente d'une cascade

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    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "rgba(229,230,232,1)",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Descente d'une cascade",
  "manifest_version": 2
}