Examine source code of Site Palette

{
  "manifest_version": 3,
  "name": "Site Palette",
  "version": "2.25",
  "description": "Site Palette generates a color palette from any website, allowing designers to use it as a reference in their work.",
  "browser_specific_settings": {
    "gecko": {
      "id": "{fa1a7e70-5be1-4efc-8163-2b93696f61e6}",
      "strict_min_version": "58.0"
    }
  },
  "icons": {
    "16": "icons/Site-palette.png",
    "32": "icons/Site-palette.png",
    "48": "icons/app-icon--big.png",
    "128": "icons/app-icon--big.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_icon": {
      "16": "icons/Site-palette.png",
      "32": "icons/app-icon.png"
    },
    "default_title": "Grab colours from this page!"
  },
  "permissions": [
    "storage",
    "tabs",
    "scripting"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "scroller.js",
        "getPalette.js",
        "sitePalette.js",
        "login.js"
      ]
    }
  ],
  "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'self'"
  }
}