Examine source code of Chameleon Theme

{
  "description": "A Dynamic Theme that changes the browser background color to the dominant color from the current website palette.",
  "manifest_version": 2,
  "name": "Chameleon Theme",
  "permissions": [
    "theme",
    "<all_urls>",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js",
      "vibrant.js"
    ]
  },
  "version": "2.2resigned1",
  "applications": {
    "gecko": {
      "strict_min_version": "55.0",
      "id": "{a3137db5-c86d-436b-abff-b9413e52cabd}"
    }
  }
}