Examine source code of Make YouTube Red Again

{
  "manifest_version": 3,
  "name": "Make YouTube Red Again",
  "version": "1.1",
  "description": "Revert YouTube's colour scheme to when the accent colour was pure red with no magenta gradients.",
  "permissions": [
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.youtube.com/*",
        "http://www.youtube.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_end"
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "youtube.css",
        "red_favicon.png"
      ],
      "matches": [
        "https://www.youtube.com/*"
      ]
    }
  ],
  "host_permissions": [
    "http://www.youtube.com/*",
    "https://www.youtube.com/*"
  ],
  "action": {
    "default_popup": "popup.html"
  },
  "icons": {
    "512": "logo512.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{1b1f04c0-0502-467a-810f-5f49f6e850e7}"
    }
  }
}