Examine source code of ColorShift

{
  "manifest_version": 3,
  "name": "ColorShift",
  "description": "A dynamic theme that changes color based on the active tab icon.",
  "version": "0.0.1",
  "author": "DPende",
  "developer": {
    "name": "DPende",
    "url": "https://github.com/DPende"
  },
  "icons": {},
  "background": {
    "scripts": [
      "index.js"
    ]
  },
  "permissions": [
    "theme",
    "activeTab",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{a4848eb9-7b24-4585-b079-243ffc79d8e1}"
    }
  }
}